SummaryThe total quantity of zinc in the ejaculates of smokers was sipficantly lower than in non‐smokers. This was not related to a significant increase in the quantities of seminal cadmium or lead, or to a decrease in sperm quality in the smoking group. It appears that tobacco consumption may have to exceed 20 cigarettedday before a noticeable increase in seminal cadmium can be recorded. It is suggested that this reduction in zinc secretion may jeopardize the content of chromatin zinc, and thereby the stability of the sperm chromatin. This may then contribute to reproductive failure or have consequences for fetal developmen