Increasing costs of soluble phosphate fertilizers and possibility of environmental pollution necessitate judicious choice of phosphorus (P) fertilizer, the quantity of which determines total fertilizer cost in crop production enterprises. As such, the trial to find out the suitability of rock phosphates was conducted to ensure economic returns to the growers and guarantee sustainable production. Polybag oil palm (Elaeis guineensis) seedlings were treated in two soil types (three replicates in RCBD) to three levels of P (0, 7.56 and 15.12 g P2O5 palm-1) using single super phosphate, SSP (18% P2O5); Ogun rock phosphate, ORP (30% P2O5) and Crystalliser, CRYS (talc + Sokoto rock phosphate mixture) (21% P2O5) in 1998/1999. Plant vigour attributes (stem girth and leaf area) were evaluated at 3, 6, 9 and 12 Months After Planting (MAP). Phosphorus application of the three sources proved quite beneficial, as untreated plants were less vigorous than treated ones. Treatments shortened the period (by about 3 months) that seedlings had to grow prior to being transplanted or sold to other growers. Seedlings` responses to the sparingly soluble, cheap and readily available P sources (ORP and CRYS) were equal or better than to the soluble, expensive and less available SSP in both soils, guaranteeing net returns to the growers when the former are substituted for the latter. The studies revealed that the maximum returns (B:C = 1.12) were registered when ORP was applied at 7.56 g P2O5 palm-1.