Prosody is a fundamental aspect of speech communication through which (un)truthfulness and (in)sincerity of speech can be identified. The focus of the study is on the prosodic features of (in)sincere compliments among EFL learners. Twenty male and female EFL learners were selected through Oxford Quick Placement Test. The participants did role-plays based on situations on compliment topics and their voices were recorded in a recording studio. The produced compliments were transferred to Praat software for acoustic analysis. Also, two native speakers (one male and one female) were requested to read the produced compliments both in a sincere and insincere manner. Their voices were transferred to Praat software for acoustic analysis to establish the baseline of the study. The prosodic features of the participants’ voices were compared with those of native speakers to determine the (in)sincerity of the compliments on a 5-point scale. Results showed that sincere compliments are produced with a higher pitch. Concerning the gender of the participants, males were sincerer than females. Regarding the proficiency level of the participants, there was no significant prosodic feature in determining the sincerity of their compliments. Both intermediate and advanced groups were similar to native speakers in giving sincere compliments. The results of the study open up new horizons for the importance of vocal cues in evaluating sincerity in speech acts.