Male infertility is one of the most important health problems. It can be caused by drugs, especially those used for mental illnesses. Poor nutrition can also affect male fertility as well as mental health. L-carnitine as a natural supplement shows promising effect in preserving male fertility. The purpose of this study was to test whether L-carnitine is protective against lithium and carbamazepine induced male infertility in protein malnourished rats. Forty-eight adult male albino rats were divided in six groups. Lithium and carbamazepine were administered in combination and L-carnitine was given as protective against deteriorating effects on male fertility. This was undergone in both normal feeding and protein malnutrition conditions. Oxidative stress parameter (MDA), testicular testosterone, testicular TNF and gonadosomatic index (GSI) were evaluated. Lithium and carbamazepine administered groups showed significant increase in testicular MDA and marked decrease in testosterone and GSI. Testicular TNF was modestly decreased. L-carnitine administration showed significant reduction in tissue MDA while it showed increase in testosterone and GSI. There was no effect on testicular TNF. Lithium and carbamazepine combination caused decline in male fertility parameters. This decline was more prominent in the protein malnourished animals. L-carnitine caused improvement in male fertility. Its effect was stronger in the normally fed animals.