Oral communication is one of the main reasons language learners attend language classes. As pronunciation is among the most significant aspects of oral communication, this study attempted to see how learning-oriented assessment (LOA) could affect pronunciation learning of Iranian EFL learners. To this end, 64 language learners in a private language institute in the city of Amol, Iran, were given NELSON language proficiency test as homogeny test. A total of 40 learners were selected and assigned to two groups. Both groups were given a researcher-made pronunciation test at the beginning and two pronunciation tests (immediate and delayed tests) at the end of the treatment. The control group participants followed the conventional curriculum of the language center and the experimental group learners went through LOA treatment. The findings of the study revealed that LOA can positively affect pronunciation learning of Iranian EFL learners. In addition, it was observed that LOA has a significant effect on the participants' retention of pronunciation knowledge. This study can have pedagogical implications for language teachers and teacher trainers.