Early detection and making diagnosis is important and essential to start the stimulation of the mentally retarded child in an adequate way and at due time.It is based among other factors, on the so-called critical period, in the maturation of certain psychophysical functions and the fact that although retarded, the development of mentally retarded children follows the same pattern as in normal ones. Our survey deals with the questions and problems concerning the early detection and making a diagnosis and especially with the informing of the parents about the actual condition and its less painful acceptation. We dwell on the informing of the parents about the Down’s syndrome of their child, which can be recognized immediately after birth.It is important when, who, how and what to tell the parents. We also discuss certain reactions of the parents who have been later informed about the condition of their child, based on our experience.