PURPOSE: To verify the occurrence of the phonological process of plosives and fricatives devoicing in children with phonological disorders. The following variables were involved: most affected phonemes, severity of phonological disorder, and age. METHODS: Participants were 50 children, with an average age of 6 years and 5 months. Speech data were collected by means of the Avaliação Fonológica da Criança (Phonological Assessment of Children) and submitted to contrastive analysis. The severity of the phonological disorder was determined by the Percentage of Consonants Correct - Revised. Then, it was analyzed which plosive and fricative phonemes were affected by the devoicing strategy, with occurrence greater than 40%. Afterwards, statistical analysis was performed. RESULTS: The simultaneous comparison the six phonemes showed no difference regarding the use of devoicing. Difference was found only for /g/ x /v/, and for /b/ x /v/. Regarding age, no significant difference was found. As for the severity of phonological disorder, difference was found only for the variable devoicing of /d/ and /ʒ/. CONCLUSION: The phonological process of devoicing have high occurrence in children with phonological disorder, with higher prevalence for stops consonants. Age does not influence the occurrence of this process, and the severity of the phonological disorder is a relevant factor to its use, with higher prevalence in the most severe degrees.