Objectives: To measure the prevalence and impact of pain and to determine factors associated with pain among inpatient intravenous drug users with HIV in Hai Phong, Vietnam. Population: 354 intravenous drug users with HIV hospitalized in Viet-Tiep hospital. Method: descriptive and acrosssectional study. Results: Prevalence of pain in the last 24 hours among IDUs with HIV was 90 percent. Pain had moderately or severely impacts on working (92.8 percent), sleep (79.9 percent), activity (84.6 percent), walking (73.6 percent), enjoyment of life (65 percent), relationships (55.4 percent) and mood (54.8 percent). Conlusions: Moderate and severe pain is prevalent among IDUs with HIV in Hai Phong. Pain moderately or severely impacts quality of life and ability to perform activities in daily life.