Disclosed is a portable therapeutic fluid dispensing device. The fluid dispensing device includes a reusable part (100) comprising a reusable part housing including at least a controller and a first portion (186) of a driving mechanism, and a disposable part (200) comprising a disposable part housing including at least a reservoir (220) to retain therapeutic fluid, an outlet port to which the therapeutic fluid is dispensed, a fluid conduit providing fluid communication between the reservoir and the outlet port, and a second portion (112) of the driving mechanism. At least a portion of the disposable part housing defines at least a portion of the reservoir. Also, the second portion of the driving mechanism is mechanically couplable to the first portion of the driving mechanism upon connection of the disposable part to the reusable part.