A mobile communication device with an ergonomic feature comprises a housing, a display unit, a first key module, and a second key module. The display unit is arranged on a lower part of one face of the housing, and the first key module is arranged on the housing on the same face as the display unit to locate closely above the display unit. The first key module comprises a plurality of upside keys which are arrayed into a laterally symmetric hexagonal configuration. The second key module comprises a plurality of lateral keys located on one of two opposite lateral surfaces of the housing. The keys of the two key modules are so arranged on the housing that either a right-handed or a left-handed user can conveniently operate the keys not only with a thumb but also the other four fingers while holding the device with one single hand.