Background: Heavy rain hit Pakistan including Sohbatpur district in August 2022 with subsequent flash floods. Study was carried out to assess the impact of flooding on incidence of malaria in Sohbatur district.  Methods: This observational retrospective study compared malarial data during rainfall seasons in Sohbatpur community in flood 2022 with those of corresponding rainfall seasons of previous two non-flood years 2020 and 2021. Results: A marked increase of malaria cases and incidence rate was observed in 10 sentinel malaria notification sites in district (IR>4.01/100,000 person­ days in 2019 [95 % CI: 6.13-7.04] and 5.41 in 2020 [95 % CI: 6.33-6.51] to 11.24 in 2022 [95 % CI: 9.15-9.44]; P< 0.0001), with peaking of incidence rate in 5-15 years’ age group. An evident increase in slide positivity rate (P< 0.0001) was observed in 4-week period of 20222 (SPR = 18.16% [95 % CI: 20.40 ­21.32%]) compared with same periods in 2020 (SPR = 8.72% [95 % CI: 8.36 ­9.08%]) and 2021 (SPR = 12.62% [95 % CI: 13.14 ­14.88%]), with more marked rise of SPR in 5-15 years’ age group. Hospital OPD incidence proportion in 2022 was 22.3% (95% CI: 17.11-­19.22%) compared to 10.15% (95% CI: 6.48-­6.91%) in 2020, and 9.17% (95% CI: 7.82-­9.21%) in 2021. The 5-15-year age group was responsible for overall rise in proportion of malaria cases in 2022. Incidence proportion of severe malaria cases increased to 22.5 % (95 % CI: 20.12 to 21.50 %) in study period of 2022 compared to 19.8 % (95 % CI: 18.6 to 21.0 %) in 2020 and 18.4 % (95 % CI: 17.4 to 19.5) in 2021. Conclusions: Study revealed a significant increase in incidence rate of malaria in Sohbatpur following flash flood of August 2022. The flooding had highest impact on malaria incidence of age 5-15 years’ age group.