PURPOSE: To verify the influence of extra linguistic factors in the process of consonant cluster reduction (REC) in children with atypical phonological development. CASE REPORT: The sample was composed of the speech corpus (2200 words in total) of 161 children, aged 4-8 years, with atypical phonological development. The words were collected through the first speech evaluation, which was carried out by using a phonological assessment of children (Avaliação fonológica da criança, AFC). The independent variables analyzed were age, level of acquisition, severity, grammatical class, and gender. We used the statistical program Varbwin for data analysis, with p values < 0.05 considered significant. The following probabilistic parameters were used: .50 to .59 neutral, favoring greater than .59, down .50 not greater. The program selected age, level of acquisition, and severity as significant variables. REC increased throughout the age range of 5.0 to 5.11 years, indicating that this process is most likely to occur at these ages. The results of the acquisition levels agree with the phonological acquisition, showing that the acquired absent and not to the occurrence of the REC, showing a change in speech. However, deviations between severe and moderately severe classes were favoring the phonological process analysis, probably indicating greater impairment of phonological children. CONCLUSIONS: The REC process is most likely to occur during the fifth year and the severity of the disorder is associated with this process, with more severe disorders showing a higher likelihood of REC.