Ths study was undertaken to investigate the prevalence of phobic reactions among the patients referred to the University of Teheran Psychiatric Hospital during 1975. It was found that about 10% of the total population studied manifested symptoms of phobia, which of course indicate different therapeutic modality to be considered in their treatment. One could easily notice that this proportion is much higher than what has been reported by Marks. It was further found that darkness, nyctophobia, necrophobia, ochlophobia, ailurophobia and pet animals and fear of cancer and syphilis accounted for 79% of the phobic cases studied.