The significance of peer assessment is highlighted in different learning contexts and researches. However, studies on peer assessment are still limited in the Sri Lankan ESL context. The present study examines the correlation between the peer assessment and the development of the presentation skills of ESL adult learners. The sample of this study consists of 45 students studying in a higher educational institute. The students received peer feedback for the oral presentations they made. A pretest and a posttest were carried out before and after the oral presentation sessions. The marks of the pretest and posttest were analyzed using SPSS data analysis package. According to this study, there is a positive effect on the peer assessment in the development of the presentation skills of ESL adult learners. At the pedagogical level, the findings of the study are essential for the teaching and learning context of Sri Lanka.