Controlled clinical trials studying the influence of hospital practices on breastfeeding duration were combined using meta-analysis. Nine studies were selected. Supplementation demonstrated a negative clinical effect on breastfeeding duration that was not significant. Nursing support demonstrated a positive clinical effect on breastfeeding duration that was not statistically significant if there was no telephone follow-up, but was significant if there was telephone follow-up. Early contact revealed a positive clinical effect that was significant. We conclude that early contact and nursing support with telephone follow-up appear as enhancing factors of breastfeeding duration.