PURPOSE: To verify the existence of a relationship between the compensatory lengthening strategy and the different severity levels of phonological disorder, quantitatively and qualitatively classified, as well as to verify the existence of a correspondence between these severity classifications. METHODS: Twenty children with different severity levels of phonological disorder and ages ranging from five to ten years participated in the study. Phonological disorder was quantitatively and qualitatively classified for each subject. The use of the compensatory lengthening strategy was identified through acoustic analysis, using an audio-processing software (PRAAT). The collected data were statistically analyzed using the Chi-square test. RESULTS: The comparative study of the severity levels of phonological disorder, according to both quantitative and qualitative classifications, did not show statistically significant differences among the groups, regarding the compensatory lengthening strategy. A descriptive analysis of the subjects' distribution according to the severity of the phonological disorder in both classifications showed a correspondence between quantitative and qualitative classifications regarding the severity of the phonological disorder. CONCLUSION: There was no relationship between the use of the compensatory lengthening strategy and the different phonological disorder severities. Subjects' distribution based on the severity of the phonological disorder, according to the classifications used in the study, allowed the visualization of a correspondence between both classifications of the disorder.