To evaluate the impact of the 12 January 2010 earthquake on HIV cases from Haiti's national HIV surveillance system and assess the characteristics of people living with HIV 1-year before and after the earthquake.An interrupted time-series design and cross-sectional analysis.We used autoregressive integrated moving average structures to model abrupt changes to the monthly, incident HIV case counts from HIV care clinics as reported to the Haitian Active Longitudinal Tracking of HIV System (French acronym SALVH) by clinical networks (n = 3) and earthquake instrumental intensity zones (n = 4). Preearthquake and postearthquake differences in patient-level characteristics including clinical values were examined using the χ test, t tests, Wilcoxon rank-sum test.In the month immediately following the earthquake, all three clinical networks experienced statistically significant declines in cases reported: iSanté (-31.4%), Groupe Haïtien d'Etude du Sarcome de Kaposi et des Infections Opportunistes (-29.9%) and Zamni Lasante (-32.2%). Zone 8 (the most severe) was the only area with a statistically significant decline (-45.5%). Of the three clinical networks, only iSanté returned to preearthquake reporting levels by the end of our study period. Patient-level characteristics did not change dramatically after the earthquake.Despite case reporting declines, especially in clinics near the earthquake epicenter, SALVH remained intact with less impact than expected. This national system is a critical component of Haiti's strategic health information system initiative and plays a central role to HIV monitoring and evaluation efforts.