This paper both reviews the current literature and explores anecdotal information as reported by Nursing Mothers' Breastfeeding Counsellors relating to breastfeeding and the use of alcohol, caffeine, nicotine and marijuana. All of these drugs do enter breastmilk to some extent and can have a detrimental effect on the production, volume, composition and ejection of breastmilk, as well as a direct adverse effect on the infant. Breastfeeding mothers should be encouraged to restrict their intake of these so-called recreational drugs. It is acknowledged that this is a particularly stressful period in a mother's life and that she may need additional support and practical suggestions to limit the exposure of these drugs to the infant.