PURPOSE: To identify the prevalence of phonological disorders and to verify the sensitivity and specificity of the adapted Speech Disorder Screening Test (TERDAF) in first grade students of elementary school in Montes Claros, MG (Brazil). METHODS: Children were randomly assigned into cluster sampling in 56 public schools in the city. We assessed 587 children with a mean age of 6 years and 6 months using the adapted TERDAF; to verify the test's sensitivity and specificity, 229 of them were also assessed using the Speech Diagnosis Assessment, considered golden standard method. RESULTS: The prevalence of phonological disorders was 36.2%. The test presented sensitivity of 94.0%, but low specificity (41.1%). Considering the linguistic variations as normal production, the test had sensitivity of 86.7%, specificity of 75.3%, positive predictive value of 66.7% and negative predictive value of 90.9%. CONCLUSION: A high prevalence of phonological disorders was found. Due to the fact that most subjects did not recognize some picture and also that productions reflecting socio-cultural conditions occurred, the test must be further reviewed in order to be more accurate in the identification of phonological disorders.