Edgeworth is usually calm and level-headed, but is typically seen as a snob due to his cold, ruthless, and generally aloof nature. He has a certain lack of social skills and tact, making him very insecure and awkward around others. In fact, he was taught as a child to glare at people who looked at him, unwittingly intimidating them. He also has difficulties with some names, referring to the Global Studios mascot "Mr. Monkey" as "Mrs. Monkey", calling Psyche-Locks "Psycholocks", and referring to the robot Ponco by the name "Panko", despite the latter's numerous attempts at correcting him. Edgeworth dislikes the limelight and often tries to credit other people or circumstances for his accomplishments, and sees no value in awards or trophies. He hates showing his weaknesses, and resists other people's attempts to get involved with his problems.

Although generally loath to admit it, he cares deeply for his friends, going to great lengths to assist them, as far as chartering a private jet on short notice to help Wright. Though he often insists that Gumshoe and Faraday are little more than nuisances to him, they form a formidable team, and he greatly appreciates and respects their presence and assistance. Nonetheless, he is not always aware that he comes off as cruel or condescending, or even that he is glaring at someone.

The DL-6 Incident left him with debilitating phobias of earthquakes and elevators, as well as suffering recurring nightmares about the incident, and the thought that he might have been the killer haunted him for 15 long years. However, although the nightmares ceased to occur after the incident was resolved, Edgeworth's fear of earthquakes and elevators remained. His reaction to earthquakes, or similar effects such as air turbulence, range from shortness of breath to sobbing and curling up into a ball or even fainting. Such reactions are involuntary and stem from what had happened during the DL-6 Incident.

He is known to have a fear of heights, and when faced with situations where he would have to leave ground level (e.g., retrieving books off of a high shelf), he will often have others take on the task instead. This fear does not come from the DL-6 incident, however, as Wright is aware of it from their days in school together before the incident.[6] He may also have an allergy to pollen.[7] It's also said that he likes cows.[citation needed]

A very logic-oriented person, Edgeworth does not believe in the supernatural, even remaining skeptical after he used Wright's magatama himself. Similarly, he cannot understand romantic love and anything related to it, planning to live his life unwed. In early 2001, when Edgeworth was nine years old, someone stole his lunch money. The suspect at the time was fellow student Phoenix Wright, who had skipped P.E. that day due to a terrible cold. The next day, a class trial was held with Wright as the defendant. Everyone was shouting that Wright was the culprit, but both Edgeworth and Larry Butz, another classmate, stood up for him, saying that no one had any proof that he was responsible. The class trial ended and the three boys became almost inseparable friends. Edgeworth deduced that Butz was the thief, but admired the way the boy had stood up for Wright, so he let the issue go. Edgeworth would often talk with his friends about his father, famous criminal defense attorney Gregory Edgeworth, whom he idolized.

Edgeworth was a very bright pupil and won awards in school for various activities such as golf competitions, writing essays, and playing the flute.[3] Even back then, he hated the limelight and refuted all accolades and prizes he received. However, he broke down into tears when he failed at a task, such as his attempt at origami,[4] and went to great lengths to ensure that his next attempt was successful. Miles Edgeworth is a[2] Chief Prosecutor of the prosecutor's office. During his first four years as a prosecutor, he had a perfect win record in trials and was willing to do just about anything to get a guilty verdict for the defendant. His defeat in court at the hand of his childhood friend Phoenix Wright was the beginning of a series of seismic shifts in his attitude concerning his profession. He even quit twice, only to return each time with a fresh outlook on how he conducted his life.

By the time of the Mask☆DeMasque trials, he had become an international prosecutor who had prosecuted in five other countries, as well as being known as the top prosecutor in his homeland. His goal as a prosecutor is to seek the truth above all else, and to use the power of the law to save people.

He wears a deep red suit with a white shirt and a white ruffled cravat, although his suit was depicted to be purple in older games. His hair is a neat gray color, and so are his eyes.