Background: High maternal and neonatal mortality rates in Mozambique, are due to adolescent pregnancies, difficulties in accessing health services, traditional constraints, and gender inequalities. An implementation research project, Alert Community to Prepared Hospital in Natikiri, Nampula, Mozambique was developed to reduce maternal and newborn mortality. From 2016 to 2020, it implemented activities to improve population knowledge and function in sexual and reproductive health, and to enable community participation in maternal health services. In this paper, we assessed and discussed the impact of community participation on improving sexual and reproductive health. Methods: The “Alert Community to Prepared Hospital” was an implementation research program with community intervention and programmed mid-term evaluations. It used mixed methods research design such as descriptive quantitative surveys, qualitative focus group discussions, and interviews, applied from 2017 to 2020. Local health committees, traditional birth attendants, traditional healers, and local leaders all participated: trained in sexual and reproductive health and participated in radio discussion groups; community and hospital members of the co-management committee enabled local programming. Maternal and child health indicators were evaluated with the health unit’s statistical operational data. Quantitative data were captured in Microsoft Office Excel, analysed with SPSS21 to find the frequency, percentage, mean and standard deviation; qualitative data were registered in Microsoft Office Word and analysed with Nvivo software. This research received bioethical approvals from both the Mozambican and Canadian universities and followed all Helsinki Declaration recommendations. Results: Comparing changes from 2016 to 2019, the number of health committees operating in Natikiri rose from 7 to 20. Each committee integrated four Family Health Champions, who attained 24738 residents with health education interventions on reproductive health and rights. A theatre group developed dramas about the same key messages and presented the plays in local communities. Population access to contraceptives was facilitated, from 42% to 91% in women and from 65% to 90% in men. At Marrere Health Centre, women with four ante-natal visits rose by 185%, and children less than one year of age’ surveillance visits raised by 89%; at Marrere General Hospital’ maternity deliveries rose 60%. Conclusion: Community participation, at all levels of maternal and child health service care continuum, from families, health committees, and communities to health centres and hospitals, enhanced with complementary interventions well contextualized, sexual, and reproductive health and rights key messages broadcasted, discussed, and presented by local theatre groups, is effective in improving adolescent and adult sexual and reproductive health. Plain English summary An Alert Community to a Prepared Hospital Implementation Research Project was carried out in Natikiri, Nampula, Mozambique, from 2016 to 2020, aiming to reduce maternal and neonatal mortality rates, considered priority public health problem in this country. It deployed activities to improve population knowledge and behaviour in sexual and reproductive health and rights and enable community participation in maternal and newborn health services: classroom training, community radio discussion groups, and drama performances. Using mixed-methods research to evaluate results with local health committees, traditional birth attendants, traditional healers, and local leadership, we compared the evolution of maternal and child health indicators at health units. Comparing changes from 2016 to 2019, the number of local health committees rose, attaining 24738 residents with health education interventions, population access to contraceptives was facilitated, from 42% to 91% in women and from 65% to 90% in men, women with four antenatal visits rose by 185%, children less than one year of age’ surveillance visits rose by 89%; and hospitals’ maternity deliveries rose by 60%. Community participation in maternal and child health service care has been demonstrated to be effective in improving adolescent and adult sexual and reproductive health. Trial registration This maternal and child health study was approved by the Lúrio University Bioethics Committee (02/CBISUL/16) and the Behavioural Ethics Board at the University of Saskatchewan (BEH#15-112), and was not registered in any database. Keywords: Maternal and child health, community, family planning, health services, implementation research, Mozambique, participation, pregnancy, reproductive and sexual health.