The youthful appearance of the fifth Doctor belies his great age and experience, yet is not out of place: this incarnation of the Doctor is far more vulnerable than previous or successive ones, with a great awareness both of his and his companions' mortality. He dresses in old-fashioned cricketing clothes: a long fawn coat with red edging, cream cricketing pullover and sports shirt also trimmed in red, cream and red striped trousers and white cricket boots. A panama hat with a red hat band is usually kept folded in a coat pocket. His blue eyes and straight fair hair heighten his innocent appearance.

His seeming innocence makes the Doctor a disarming person to meet: he uses boyish charm and a friendly smile to win the confidence of others. He often goes along with someone's plan just to buy thinking time: he has a clear sense of right and wrong. The charm, however, can conceal a nervous, anxious character who is plainly worried about the course of events or the real intent of those people he encounters. Such nervous energy translates into a sense of urgency when the Doctor finally acts.

Reckless in action, the Doctor never seems completely to succeed: his solutions to problems are somehow incomplete and can have tragic consequences. His companions may even find his actions morally unacceptable: despite his abhorrence of unnecessary killing, the Doctor is not afraid to shoot an enemy if he believes it is the best and only solution. He acts for the best of motives, however, and does not mean to upset his companions.

The Doctor's carefree approach to his adventures often lands him in trouble from which he sometimes struggles to extricate himself. Although he never intentionally neglects the safety of his companions, his naive approach often endangers their lives. He can be too protective, however, even ordering companions to stay on board the TARDIS; he is angry if anyone ever disobeys such an order. The Doctor will risk his own life to save his friends if they are in trouble and comfort them if they are afraid or upset: he often has to reassure Tegan with the words 'Brave heart, Tegan.'