Latar Belakang: Menstruasi merupakan keadaan fisiologis perubahan hormon yang dialami setiap bulannya oleh perempuan. Indeks massa tubuh (IMT) dilaporkan memiliki korelasi dengan meningkatnya prevalensi dismenore pada perempuan. Tujuan Penelitian: Mengetahui hubungan indeks massa tubuh (IMT) dengan nyeri menstruasi (dismenore) pada mahasiswi Fakultas Kedokteran Universitas Pelita Harapan. Metode: Penelitian ini menggunakan studi analitik dengan pendekatan potong lintang (cross-sectional) dengan metode pengambilan sampel non probability sampling melalui convenience sampling pada 152 sampel mahasiswi Fakultas Kedokteran Universitas Pelita Harapan yang memenuhi kriteria inklusi penelitian menggunakan penilaian WaLIDD score dan perhitungan IMT.Hasil: Berdasarkan gambaran indeks massa tubuh (IMT) diperoleh data subjek dengan IMT kurus 24 (16,6%), IMT normal 92 (63,4%), dan IMT 29 subjek (20%). Subjek tanpa dismenore 22 (15,2%), sedangkan diperoleh data klasifikasi dismenore tingkat ringan 63 (43,5%), dismenore tingkat sedang 45 (31%), dan dismenore tingkat berat 15 (10,3%). Didapatkan 29 subjek mengonsumsi NSAID, dimana 23 diantaranya merupakan subjek dengan IMT tidak normal (79,3% dari total pengguna NSAIDs). Berdasarkan hasil analisis data menggunakan Chi-square didapatkan hasil p-value 0,395 sehingga tidak terdapat hubungan antara IMT dan dismenore. Kesimpulan: Tidak ditemukan adanya hubungan yang signifikan antara IMT dengan dismenore pada mahasiswi Fakultas Kedokteran Universitas Pelita Harapan. Referensi: 27 (2015-2023) / Background: Menstruation is a physiological state of hormonal changes experienced monthly by women. Body Mass Index (BMI) has been reported to have a correlation with the increased prevalence of dysmenorrhea in women. Objective: To determine the relationship between Body Mass Index (BMI) and menstrual pain (dysmenorrhea) in female medical students at the Faculty of Medicine, Universitas Pelita Harapan. Method: This study used an analytical study with a cross-sectional approach and non-probability sampling method through convenience sampling on 152 female medical students at the Faculty of Medicine, Universitas Pelita Harapan, who met the inclusion criteria of the study. The WaLIDD score and BMI calculation were used for assessment. Results: Based on the Body Mass Index (BMI) profile, the data showed 24 subjects (16.6%) with underweight BMI, 92 subjects (63.4%) with normal BMI, and 29 subjects (20%) with overweight BMI. Of the subjects, 22 (15.2%) had no dysmenorrhea, while the classification of dysmenorrhea severity showed 63 (43.5%) with mild dysmenorrhea, 45 (31%) with moderate dysmenorrhea, and 15 (10.3%) with severe dysmenorrhea. Additionally, 29 subjects reported using NSAIDs, of which 23 had abnormal BMI (79.3% of total NSAID users). The Chi-square analysis yielded a p-value of 0.395, indicating no significant relationship between BMI and dysmenorrhea. Conclusion: No significant relationship was found between BMI and dysmenorrhea in female medical students at the Faculty of Medicine, Universitas Pelita Harapan. References: 27 (2015-2023).