Tooth agenesis in human being is the most common congenital anomaly associated with dental development. Mutations in many genes such as MSH homeobox 1 (MSX1), paired box gene 9 (PAX9), ectodysplasin A (EDA) and EDA receptor (EDAR) have been associated with familial form of this condition.However, in large majority of patients, genetic cause could not be identified. The primary aim of present study was to identify the causative mutation(s) in these genes in Saudi Arabian families diagnosed with non-syndromic form of disease.