We demonstrate the preparation of composite photovoltaic devices by using the blends of multi-armed CdS nanorods with conjugated polymer, poly2-methoxy-5-（2＇-ethylhexyloxy）-1,4-phenylenevinylene] （MEH-PPV）. Multi-armed CdS nanorods are prepared by thermolysing single precursor cadmium ethylxanthate Cd（exan）2] in pure hexadecylamine solution under ambient conditions. The photoluminescence of MEH-PPV can be effectively quenched in the composites at high CdS nanocrystal （nc-CdS）//MEH-PPV ratios. Post-treatment of the multi-armed CdS nanorods by refluxing in pyridine significantly increases the performance of the composite photovoltaic devices. Power conversion efficiency is obtained to be 0.17% under AM 1.5 illumination for this composite device.