A laboratory study of the biology of Corcyra cephalonica (Staint.) was made at 30°C and 70% r.h. on sorghum. The number of eggs laid per female, oviposition period, development time and survival from egg to adult were determined. The data were used to estimate the finite rate of increase and the intrinsic rate of natural increase of the moth. For the finite rate of increase (λ) the estimated value was 18 per lunar month, corresponding to an intrinsic rate of natural increase (r) of 2.9. The results are compared with published data and it is concluded that the pest potential of C. cephalonica has been, hitherto, underestimated.