- "It is possible to move a relationship along too fast and ultimately marry too hastily. You could find a few years down the line that the person isn't really right for you, and then what happens if you meet the right person, someone who REALLY EXCITES you and makes you feel ALIVE, but you can't ACT upon it because you're TRAPPED in a STALE, albeit comfortable MARIS... marriage"
- ―Niles about his marriage to Maris
Born in Seattle, Washington, in 1957, to Hester Crane, a psychiatrist, and Martin Crane, a police detective. Although the exact date of Niles' birth is never revealed, he's roughly two years younger than Frasier.
Like Frasier, Niles was named for one of his mother's lab rats. Also like Frasier, Niles was a sensitive child when growing up, and a frequent target for bullies. As a result, he was quite close to his older brother, and at the same time fiercely competitive with him. Like Frasier, Niles also preferred fine arts, music, and intellectual pursuits to activities like sports, though he excels in sports like squash and croquet.
Niles' success in school led to his attendance at Yale University in New Haven, Connecticut (like his counterpart David Hyde Pierce) as an undergraduate, and the Yale School of Medicine for both his M.D. and Ph.D. in psychiatry. He subsequently attended the University of Cambridge in Cambridge, England, where he was a postdoctoral fellow while completing his professional training. This further highlights the close competitive relationship with his brother, Frasier, who attended Harvard University in Cambridge, Massachusetts as an undergraduate, then Harvard Medical School for both his M.D. and Ph.D. in psychiatry, subsequently followed by his own postdoctoral fellowship at the University of Oxford in Oxford, England.
Niles describes his profession as "the saving grace of my life" and is greatly respected professionally. He runs his own Jungian practice (Frasier is a Freudian) and has had his research published in several psychiatric journals. Niles often compares his own career to that of his brother, and early in the series makes frequent wisecracks about the "pop psychiatry" that Frasier practices through his radio show. Over the course of the show his remarks dwindle to occasional jabs for the purpose of humor. It is revealed that Niles lashed out at his brother due to jealousy, as he felt that he did not receive the praise and recognition due for his hard work, whereas Frasier's face is seen on "the side of buses." This sibling conflict is one of the main ones explored in the series.
Niles is fastidious, snobby and fussy, and has gourmet tastes. He is also loyal, chivalrous and incredibly loving which more than makes it up in the eyes of his loved ones. He is, in the earlier seasons during his marriage to Maris. He likes and enjoys classical music, fine wine and French food which he himself cooks, and frequently obsesses about knowing the right people and climbing the social ladder. Niles is also very intelligent. Niles has a 156 IQ, well above the Mensa median (which is typically around the low 130s).
Niles has a long list of phobias and medical conditions, many of which are clearly psychosomatic. Most prominently, he is quite mysophobic, given to wiping his hands after human contact and wiping down chairs in public places before sitting on them. He has nose bleeds when he tells a direct lie, and he faints at the sight of blood. When extremely stressed, he is prone to panic attacks and fits of hyperventilation which have, on more than one occasion, seen him lose consciousness. He also suffers from a long list of allergies, some of which are exceedingly rare.
He is seemingly hopeless at sports, barely able to catch objects even after simple throws. However, in some episodes he is shown to be fair at basketball. On one occasion, while attending a basketball game, he is fortuitously invited on court during the game's intermission to try his skill (or luck) at scoring from half court, and much to the astonishment of his brother and father (and himself), Niles makes the impossible throw. The brothers are often seen coming or going to squash matches, though Martin once commented in disbelief, "You have to wonder what happens on that squash court." Accompanying Martin on the shooting range one day, Niles discovered that he is an excellent marksman. He is a fair fencer, and has had some lessons in kickboxing. On other occasions he has expressed interest in lifting weights and taking karate lessons, but these ventures are typically laughed at by his father and brother and often amount to nothing. He is also a master speller, having come close to winning the national spelling competition as a youth.
He drives a Mercedes-Benz with the license plate 5HR1NK. In the latter half of the series Niles drives an E55 AMG Mercedes (S9:E21 "Moons Over Seattle), but in a second season episode, he states that he drives a Mercedes-Benz E320. He's stuck with a Hatchback in a few episodes, much to his own horror.
- Niles has a 156 IQ
- Niles started practicing psychiatry in 1980.
- Martin's dad, Grandpa Crane, took Niles to Orsini's for his 8th birthday
- His last line is "I'll miss the coffees"
- Niles and Daphne's son David is named after Frasier co-creator David Angell who was killed, along with his wife Lynn, in the crash of American Airlines Flight 11 in the September 11, 2001 attacks.
- Niles' mentioned allergies include: