This study sheds light on the relationship between the Sonority Sequencing Principle (SSP) and syllable structure in Sabzevari, a Persian vernacular spoken in the Sabzevar area of Northeast Iran. Optimality Theory (OT), as a constraint-based approach, is utilized to scrutinize sonority violation and its repair strategies. The results suggest that obedience to the SSP is mandatory in Sabzevari, as shown through the treatment of word-final clusters in Standard Persian words which violate the SSP. These consonant clusters are avoided in Sabzevari by two phonological processes: vowel epenthesis and metathesis. Vowel epenthesis is motivated by final consonant clusters of the forms /fricative+coronal nasal/, /plosive+bilabial nasal/, /fricative+bilabial nasal/, /plosive+rhotic/, /fricative+rhotic/, and /plosive+lateral/. Metathesis, as another repair strategy for sonority sequencing violations, occurs when dealing with final consonant clusters of the forms /plosive+fricative/ and /fricative+lateral/.