In order to scrutinize the phosphorus acquisition efficiency of sunflower from sparingly soluble P source i.e. Rock Phosphate (RP), a pot research was conducted by growing sunflower (Helianthus annuus L.) in P deficient environment at research area, College of Agriculture, University of Sargodha in year 2018. The experiment was laid out in a complete randomized design (CRD) with eight treatments which were replicated four times. The treatments plan includes T1 = NK + P0 (Control); T2 = NPK (Recommended rate); T3 = NK + RP at 7 g pot-1; T4 = NPK + RP at 7 g pot-1; T5 = NK + RP at 7 g pot-1 + Wheat straw at 14 g pot-1; T6 = NK + RP at 7 g pot-1 + Wheat straw at 28 g pot-1; T7 = NK+RP at 7 g pot-1 + Rice straw at 14 g pot-1; T8 = NK + RP at 7 g pot-1 + Rice straw at 28 g pot-1. Observations regarding P accumulation, plant P concentration, P uptake efficiency and PE ratio were recorded using standard procedures and obtained data was analyzed statistically with a statistical software Statistix 8.1 analysis of variance technique and significant of treatments was tested using LSD test at probability level of 5%. The maximum P accumulation (178.37 mg P pot-1), P uptake efficiency (1.90) and PE (phosphorus efficiency) ratio(747.15 g DM (g plant-1) of sunflower was observed with application of NK + Rock phosphate at 7 g/pot + Wheat straw at 28 g pot-1 (T6) in cultivar Hysun-33. While, the lowest value of P accumulation (89.13 mg P pot-1), P uptake efficiency (1.18) and PE ratio (605.0 g DM (g plant-1) was noted under NK + P0 (T1) treatment in Agwara-3. Among the tested sunflower cultivars, Hysun-33 showed superiority over Agwara-4.