This paper proposes a three phase interleaved high gain DC-DC converter for photovoltaic (PV) applications. Interleaving technique reduces the input current ripple and current stress on the power switch while simultaneously handling high power. The voltage gain is extended by using a voltage lift capacitor, coupled inductor and voltage multiplier cell. Since voltage gain extension is realized at the secondary side of the coupled inductors, the voltage stress on the switches is only a fraction of the output voltage. Experimental results obtained from a 24V/260V, 500W prototype converter proves the converter suitability for high step up voltage conversion. © 2017 The Authors. Published by Elsevier Ltd.