Cleft palate is a congenital orofacial malformation which causes defects in the lips and palate and gives a negative effect on speech sounds. Performing surgical procedures early is recommended first because it affects major development events such as infant feeding and early speech acquisition. Considering that speech problems may remain even after anatomical improvement and functional recovery have been achieved by surgery early in the child’s development, speech pathologists try to evaluate speech sounds carefully and provide appropriate interventions. Accurate understanding and analysis of speech sounds in patients with cleft palate are essential for timely interventions and good prognosis. The present case of a patient who had not undergone surgical, orthodontic, or speech treatment until adulthood, which is rare in the current clinical practice, wherein surgical procedures and interventions are performed in almost all cases with cleft palate. In the speech analysis, the patient showed a moderate nasal emission, and most consonants were hypernasal and weakened. Furthermore, compensatory articulations such as pharyngeal stops and glottal stops were observed frequently, and the score of consonant accuracy was low. This report provides useful information about the primary effect of cleft palate on speech sounds and various cleft palate speech patterns for diagnosis of speech disorders.