The causes of Clift lip are not so specific, but the presence of clefts in a family increases the chances.

Other causes of cleft lip are vitamin deficiency and taking poor medication, and consumption of large amount of alcohol.

Exposure to smoking environment in early pregnancy, exposure to x-rays at an early stage of pregnancy may also predispose the unborn baby to the condition of cleft lip.

The World Health Organisation (WHO) so advises pregnant women to be careful.