We investigated physician awareness of the diagnosis of beta thalassemia minor as suggested by RBC indices obtained from routine electronic counts; and, the knowledge of the carriers of their genetic trait. Out of 17,000 counts, 324 were compatible with the diagnosis of beta thalassemia minor, but, only 175 (54 per cent) were identified by physicians as possibly thalassemic and in 47 of these (27 per cent) was the diagnosis verified. Twenty-four of 39 interviewed patients in whom the diagnosis of beta thalassemia minor was established knew about their carrier state.