PerMed-MM: A Multimodal, Multi-Specialty Persian Medical Benchmark for Evaluating Vision Language Models

AbstractWe present PerMed-MM, the first multimodal benchmark for Persian medical question answering. The dataset comprises 733 expert-authored multiple-choice questions from Iranian National Medical Board Exams, each paired with one to five clinically relevant images, spanning 46 medical specialties and diverse visual modalities. We evaluate five open-source and five proprietary vision language models, and find that reasoning supervision and domain-specific fine-tuning yield performance gains. Our cross-lingual analysis reveals significant unpredictability in translation-based pipelines, motivating the need for benchmarks that support direct, native-language evaluation. Additionally, domain- and modality-level analysis uncovers meaningful variation in model behavior often masked by aggregate metrics. PerMed-MM is publicly available on Hugging Face.