Point mutations in the androgen receptor gene cause androgen insensitivity syndromes, clinically characterized by masculinization defects in karyotypic males due to endorgan resistance to androgenic steroids. Characterization of these mutations with single strand conformation polymorphism analysis utilizing radioactive PCR can serve as a diagnostic tool for molecular subclassification of these syndromes. It is the basis for genetic counseling and for therapeutic decisions. Here we report an improved non-radioactive single strand polymorphism analysis for rapid detection of androgen receptor gene mutations in affected individuals. In addition to previously reported mutations, 9 patients with clinical features of androgen resistance were studied. While one insertion mutation was detected, in all other patients different point mutations initiating amino acid substitutions were characterized.