Autism is a lifelong developmental disability that causes delays in verbal and nonverbal communication and social interaction as well as ritualistic and compulsive behaviors (Berkeley et al., 2001; Loovis, 2000). Aquatic exercises promote not only physical fitness and motor skill development but also psychological and cognitive development through carefully planned and implemented programs (Lepore, 2000). Research show that aquatic exercises provide unique opportunities to learn cognitive abilities for autistic individuals (Joyce-Petrovic et al., 1994). In literature, it is stated that a constant time delay procedure was an effective way of teaching single and chain behaviors for special populations in different age groups and disabilities (Gast et. al., 1991; Mattingly and Bott, 1990; Tekin et. al., 2001). Although there have been studies about the effects of constant time delay procedures on different disabilities in the literature, there had been no research especially for the effects of constant time delay procedures on aquatic play skills of children with autism. Therefore, the purpose of this study is to determine the effects of constant time delay procedures on aquatic kangaroo, cycling, and snake play skills of children with autism. A single subject multiple probe model across behaviors with probe conditions (Blackhurst et. al., 1994) was used to determine the effects of the intervention. Four male children with autism, ages 7-9 years, and four trainers participated in this study. Data were collected over the course of 10-weeks, with sessions three times a week. A single opportunity method (Snell and Brown, 2000) was used to determine the success rate of target play skills in baseline, intervention and generalization phases. The results of the study were analyzed via graphic illustrations. Results show that all subjects increased their correct target skills in a significant amount during the intervention phase. In addition, subjects maintained their successful play skills during the first, second, and forth weeks of generalization phases. The results of this study show that constant time delay procedure is an effective way of increasing and maintaining aquatic play skills of children with autism. However, this study has several limitations, such as the characteristics of participants, tests, and the measurements that were applied. Therefore, further studies should address the effects of constant time delay procedure on different play skills, gender, ages and participants of children with autism.