The airline has had the largest market share in the domestic Taiwan market in recent years, and has expanded to include international flights. A few of its McDonnell Douglas MD-90 aircraft have been repainted and are flying for parent carrier EVA Air due to overcapacity. In recent years, Uni Air has launched services to international destinations from the southern Taiwanese port city of Kaohsiung. In 2007, the airline received permission to begin flights to Japan.
UNI Air has operated two-class services, with domestic business- and economy-class seating. Business-class passengers have access to EVA Air's Evergreen Lounges. UNI Air's predecessor, Makung International Airlines, operated a fleet of BAe 146 series jet aircraft. These aircraft were sold when Uni Air was formed. Uni Air's IATA Code is B7, its ICAO code is UIA, and its callsign is Glory. In 2012, Uni Air unveiled a new livery and tail/logo on a MD-90 aircraft.
The airline operates mainly to domestic destinations, but also operates scheduled international flights to Bangkok, Hanoi and Seoul from Kaohsiung and chartered flights to Bali and Jeju from Kaohsiung. Uni Air's destinations (as of January 2013) are:
• On August 24, 1999 on an MD90, Uni Air Flight 873 has just landed at Hualien and was rolling on Runway 21, when an explosion was heard in the front section of the passenger cabin, followed by smoke and then fire. The pilot immediately braked, brought the aircraft to a stop on the runway. Then, after lowering the passenger evacuation slides and initiating an emergency passenger evacuation, the pilot proceeded to call the tower for help. Upon receiving this call, fire squads at both the Hualien Airport and the Air Force Wing rushed to the scene to extinguish the fire. The fire was eventually put out at 13:45. While the upper part of the fuselage was completely destroyed, 90 passengers plus the crew of 6 was safely evacuated. Casualties included 14 seriously wounded passengers and another 14 that suffered minor injuries. Most of the wounded passengers suffered burns. Fragments produced by the explosion struck 1 passenger.