Maternal exposure to drugs and chemicals is increasingly being recognized as adversely affecting the developing fetus. To date, a very large number of fetuses have been exposed in utero to cocaine and cigarette smoke. Neonatal hair as a biological marker for fetal exposure in cocaine and nicotine has emerged as an excellent tool in correlating in utero exposure and outcome. However, a limiting factor is the sparsity of neonatal hair. We report on the first method that allows determination of both cocaine and nicotine as well as their metabolites in the same hair samples.