The effects of irrigation timing and plant density on the main morphological and agronomic characters of cotton were investigated over five years from 1987 to 1991 in Southern Italy. Five irrigation levels were combined with four plant densities (6, 9, 12 and 15 plants per m2). Times and volumes of irrigation were determined by thermopluviometric patterns and the phenological plant phase. The highest seedcotton yields wee obtained with high plant densities and irrigation at each phenological stage. These results confirm the importance of optimum water management in southern Italy. Irrigation increased the open bolls per plant markedly while the boll weight number per plant decreased in correlation with plant density.