This paper presents a solution technique for the optimal reactive power flow (ORPF) of alternating current direct current (AC-DC) power systems using the artificial bee colony (ABC) algorithm. A high voltage direct current (HVDC) transmission link is one of the most important network components in AC-DC power systems. In recent years there has been an increasing number of studies related to power systems with HVDC transmission links. One of them is the reactive power flow (RPF) optimization. The aim of ORPF in alternating current (AC) or AC-DC power systems is to minimize transmission line power loss under equality and inequality constraints. The relationships related to the HVDC link are incorporated into AC power system equations considering its power transfer characteristics. This paper contributes to the solution of the problem by using the ABC algorithm for the first time. The proposed method is examined on three test systems and its effectiveness in these kinds of applications is shown by the comparative results.