This paper is devoted to a new topology of a single-phase interleaved quasi-z-source inverter with active power decoupling circuit. The inverter comprises two classical completely interleaved quasi-z-source inverters to gain the benefits of passive component reduction and power quality improvement. The modulation technique applied allows maximum boost control for better utilization of the dc-link. At the same time, the input power ripple was significantly reduced. Due to the applied approach, total requirements for capacitive energy storage were decreased by 37 times as compared to the simple boost and maximum boost control without active power decoupling. As a result, the quasi-z-source stage capacitance was reduced while the output power quality was kept high. The proposed topology is ideally suitable for standalone and grid-connected single-phase photovoltaic applications.