Bloom K., Goldbloom, R. B., Robinson, S. C. and Stevens, F. E. (Departments of Psychology, Pediatrics and Obstetrics, Grace Maternity Hospital, Halifax, Nova Scotia, Canada). Breast vs. formula feeding. II. Acta Paed Scand, Suppl. 300:9, 1982.—Study 1. A prospective, longitudinal study of 249 breast feeding mothers revealed that continuance of breast feeding was positively associated with breast feeding preparation (prenatal breast feeding classp=0.04, preparation of breastp=0.02) paternal preference (p=0.02), early contact (immediate post‐delivery contact, early initiation of breast feeding and daily rooming‐in while in hospital,p=0.002), maternal education (p=0.001). and paternal occupational status (p=0.005). Duration of breast feeding was longer for multiparas (p=0.009). Mothers who stopped breast feeding in the first 6 weeks breast fed for only 18.2 days. Early termination was related (p=0.01) to reported infant behaviours (crying, waking) which were assumed to indicate hunger. Study 2. An experimental study was conducted to evaluate the effect of social support on increasing the duration of breast feeding. Three groups (N=50 each, primiparas) were randomly selected: Formula, Breast Control, Breast Experimental. During weeks 1‐4, Breast Experimental mothers were telephoned weekly by a nurse to provide informed support for breast feeding and related infant care. Social support for these primiparous mothers increased their duration of breast feeding (