Natural disasters with minimal human mortality rarely capture headlines but occur frequently and Results: in significant morbidity and economic loss. We compared the epidemic activity observed after a flood, an earthquake, and volcanic activity in Peru. Following post-disaster guidelines, healthcare facilities and evacuation centers surveyed 10–12 significant health conditions for ~45 days and compared disease frequency with Poisson regression. The disasters affected 20,709 individuals and 15% were placed in evacuation centers. Seven deaths and 6,056 health conditions were reported (mean: 0.29 per person). Health facilities reported fewer events than evacuation centers (0.06–0.24 vs. 0.65–2.02, P < 0.001) and disease notification increased 1.6 times after the disasters (95% CI: 1.5–1.6). Acute respiratory infections were the most frequent event (41–57%) and psychological distress was second/third (7.6% to 14.3%). Morbidity increased after disasters without substantial casualties, particularly at evacuation centers, with frequent respiratory infections and psychological distress. Post-disaster surveillance is valuable even after low-mortality events.