Inborn errors of metabolism (IEMs) are complex relatively uncommon medical conditions resulting in significant morbidity and mortality. Early recognition and implementation of adequate therapeutic measures are of the utmost importance in minimizing morbidity and improving clinical outcome. This article aims to address the basics of IEMs for familiarizing primary care physicians with different types of metabolic disorders, basic diagnostic strategies, newborn screening programs, and appropriate treatment strategies. Advances in diagnostic and therapeutic options are resulting in increasing longevity and improvement in the clinical outcome of many of these patients.