The present study investigated the influence of developmental level on interaction and imitation in infants and young children with autism on the basis of family videos and filmed consultation. The sample comprised 18 children with autism divided into groups according to their developmental quotient (DQ>50 and DQ<50). A quantitative evaluation was performed on video observations at four periods (10-12 months, 16-18 months, 24-26 months, after 4 years) using scales appropriate for the evaluation of interaction and imitation impairments. The findings showed that, at a very early age, infants later diagnosed as having autistic disorder show different intensities of interaction and imitation deficits according to developmental level.