To determine whether an intervention to foster breast-feeding did actually increase it and how long it lasted in nursing mothers who gave birth through caesarean section. Evaluation of a community intervention. Mother-and-Child Hospital in Málaga. Sample of 152 pregnant women who delivered their baby by caesarean section, 76 in 1996 and 76 in 1998. During 1997, activities to promote breast-feeding were organised in the health district. These included workshops aimed at primary care and specialist professionals, public events to promote breast-feeding (public feeds, photography competitions, media comment, etc), accords with institutions (university, nursing college inter al) and changes in the health services (improvement of services to new mothers and neonates; co-ordination between primary and hospital care). In 1996, only 28% of women who started feeding did so with serotherapy. In 1998 this became 85% (P<.0005). Length of breast-feeding also increased significantly (P<.215). There was greater involvement of nursing, though it was not statistically significant (P<.06), moving from 40% in 1996 to 65.2% in 1998. The campaign showed its efficacy as a method of promotion of breast-feeding, on achieving an earlier start in breast-feeding, longer duration of it and greater involvement of nurses. Practical applications included changes in hospital routines, professional training, working out of strategies and specific records for the ongoing assessment of breast-feeding.