The Haiti Population-based HIV Impact Assessment (HAPHIA) was a household-based national survey among adults (defined as individuals aged 15-64 years) conducted between July 2019 and November 2020. HAPHIA offered HIV counseling and testing with return of results to participants and collected information about uptake of HIV care and treatment services. Of 10,171 eligible households, 92.4% completed a household interview. Among 21,586 eligible adults aged 15-64 years (11,819 women and 9,767 men), 82.1% were interviewed and tested for HIV (84.7% of women; 78.9% of men). The overall response rate for adults was 75.9% (78.3% of women; 73.0% of men).