Laboratory studies were conducted to determine the efficiency of Coccinella algerica Kovàr (Coleoptera: Coccinellidae) against Pterochloroides persicae (Cholodkovsky) (Hemiptera: Lachninae) and compared against Acyrthosiphum pisum Harris (Hemiptera: Aphidinae). Feeding on P. persicae had a significant effect on predation rate by either fourth stage larvae or adults of C. algerica. The developmental period of C. algerica reared on P. persicae was significantly shorter than those reared on A. pisum (F = 51.45, d.f. = 1.19, P = 0.05). Larvae and adults of C. algerica reared on P. persicae showed a significantly greater mortality than those on A. pisum (F = 27.29, d.f. = 2, P = 0.05). Furthermore, the aphid species has an effect on body weight and fecundity of C. algerica. These results demonstrated that C. algerica is not recommended as a biological control agent of P. persicae in Tunisia.