The influence of inoculation of phosphate solubilizing bio-fertilizers in combination with sources and levels of phosphorus on nutrient uptake and yield of sunflower was studied under field condition in a vertisol. The results revealed significant increase in the weight of head, seed yield per hectare and nutrient uptake in sunflower. Inoculation of P-solubilizing bio-fertilizers in combination with application of 75 per cent recommended dose of phosphorus (RDP) in the form of single super phosphate (SSP) or in combination with 100 per cent RDP in the form of Mussoorie rock phosphate (MRP) gave almost the same yield as that of standard practice of applying SSP at 100 percent RDP without inoculation indicating the possibility of reducing input cost on P-fertilizer.