Background Malaria is one of the most prevalent and deadliest illnesses in sub Saharan Africa (SSA). Despite recent gains made towards its control or elimination in past decades, many African countries still have endemic malaria transmission. Thus, the search for disease control strategies is indispensable. This study aimed to assess malaria burden at household level in Kongo central province, Democratic Republic of Congo (DRC), and the impact of community participatory water, sanitation and hygiene (WASH) action.Methods Mixed method research was conducted in two semi-rural towns, Mbanza-Ngungu (WASH action site) and Kasangulu (WASH control site) between July 2017 to March 2018, involving 625 households (3,712 individuals). Baseline and post-intervention malaria surveys were conducted in 2017 and 2018, respectively, using the World Bank/WHO Malaria Indicator Questionnaire. In addition, an action research consisting of a six-month (September 2017 - February 2018) prospective study was carried out which comprised two interventions: (1) a community participatory WASH action aiming at eliminating mosquito breeding sites in the residential environment and a (2) community anti-malaria education campaign. The latter was implemented at both study sites. In addition, baseline and post-intervention rapid diagnostic test (RDT) for malaria was performed among respondents. Furthermore, a six-month prospective hospital-based epidemiological study was simultaneously conducted using records of patients admitted at health settings located at both study sites.Results Prevalence of positive malaria RDT among respondents decreased significantly at WASH-action site (38% vs. 20%; p < 0.05), but no significant change was observed at the WASH control site. There were 96% of respondents (heads of households) who reported at least one malaria event occurring in the previous six-month period, only 66.5% of them received malaria care at a health setting. At household level, long-lasting insecticide-treated net (LLIN) was the most commonly used preventive measure (55%), followed by mosquito repellent (15%), indoor residual spraying (IRS) (2%), LLIN-IRS combination (2%); however, 24% of households did not use any measures. Mean household malaria incidence decreased at the WASH action site; 2.3 ± 2.2 cases vs. 1.2 ± 0.7 cases (p < 0.05), whereas no significant change was noted in control site. Moreover, malaria incidence rate was highest (60.9%) among households living in proximity to grassy and/or stagnant water spots. Low household monthly income (ORa = 2.37; 95%CI: 1.05–3.12; p < 0.05), Proximity to high risk area (grassy/stagnant water spots) for malaria (ORa = 5.13; 95%CI: 2-29-8.07; p < 0.001), poor general WASH status in residential area (ORa = 4.10; 95%CI: 2.11–7.08; p < 0.001) were determinants of household malaria. Furthermore, data collected from referral health settings showed high malaria frequency, 67.4% (1,108/1,645) occurring during the first semester of 2017, including 772 (70%) of pediatric malaria cases and 336 (30%) of cases from Internal medicine departments.Conclusion Findings from this research suggest the necessity for DRC government to scale up the fight against malaria by integrating efficient indoor and outdoor preventive measures, including WASH intervention in residential environment, and improve malaria care accessibility to reduce malaria burden. This would be a step towards achieving universal health coverage (UHC) in the Congo.