The present work was carried out to investigate the development of bollworm infestations in the transplanting cotton and cotton sowing by seeds during three successive cotton growng seasons of 1993, 1994 and 1995 at Gharbia, Kafr el-Sheikh and Beheira Governorates. The in­festation by cotton bollworms, Pectinophora gossypiella (Saunders) and Earias insulana (Boisd.) in the squares, flowers and green bolls were esti­mated during the whole period of investigation for the three tested lo­calities combined. Cotton sowing by seeds harboured the highest infes­tation levels, while cotton cultivated by transplanting of cotton seedlings received less cotton bollworm infestations.