The baby's first words producing is one of the most important index of development. Development of talking is through a complex process that is influenced by both neuromaturation and human relationships (environment). It is not an imitative function in which children learn to repeat what they hear, but also it is a creative process through which children master a rule based, symbolic system. Talking development can be evaluated in 5 important dimensions: phonology, semantics, morphology, syntax and pragmatic. The receptive and expressive abilities of the child must be evaluated also. This paper discusses about the epidemiology, etiology and pathogenesis, clinical manifestations, how to assessment and make early diagnosis, differential diagnosis, management (treatment and rehabilitation) and prognosis of delayed or atypical talking in addition to above definitions. This paper also emphasizes on early intervention for children who develop significant behavior problems secondary to their communication difficulties and for whom long-term problems in social development are a major concern.