Phosphorus efficiency (PE), and its relationship with intracellular (APase) and secreted (S-APase) acid phosphatases, anthocyanin accumulation, and calcium and zinc nutrition, were compared among 8 cultivars of each of wheat, sunflower, chickpea, and lentil grown under greenhouse conditions with low and high rates of P supply in a P-deficient calcareous soil. Except for the chickpea cultivars, deficiency of P resulted in significant decreases in shoot dry weight of all the crop cultivars and led to significant decreases in root dry weight in wheat and sunflower, significant increases in root dry weight in chickpea, and no significant difference in root dry weight in lentil. PE differed greatly among species and their cultivars. On average, shoot P concentration in cultivars of wheat, sunflower, chickpea, and lentil increased by 44%, 54%, 47%, and 8%, respectively, with P supply, and the increases in P concentration differed greatly among cultivars of all species. Intracellular leaf APase activity of wheat and lentil cultivars was slightly decreased by P supply, while it was unchanged in sunflower and chickpea cultivars. However, root-secreted acid phosphatase (S-APase) activity was significantly reduced by P supply in wheat, sunflower, and chickpea cultivars. Under low-P conditions, S-APase activities of all species except sunflower were negatively correlated with PE. Phosphorus deficiency increased the anthocyanin concentration of the cultivars of wheat and sunflower, whereas it was usually decreased in cultivars of the P-efficient species chickpea and lentil. In general, concentration of Ca was found to be lower, but Zn concentration was higher, in P-efficient cultivars than in P-inefficient cultivars. The results demonstrated that PE of the cultivars clearly depends on their ability to take up P and Zn, and on secretion of acid phosphatases from their roots under P deficiency. The results also suggest that characteristics of Zn and Ca nutrition should be taken into consideration when screening cultivars of crop species for their P efficiency.