Background <p>Armed conflict can be described as human development in reverse. In addition to the direct consequences of violence, there are numerous ways in which armed conflict may have indirect effects on people’s health and well-being. Studies give varying results, and health impacts seem to differ from context to context. We aimed to determine how conflict intensity is associated with health outcomes, accounting for existing vulnerabilities and the functioning of healthcare services in countries experiencing armed conflict.</p> Method <p>This study is based on panel data on conflict intensity, vulnerability, healthcare service functioning, and health outcomes in 42 conflict-affected countries between 2000 and 2019 and uses fixed-effects panel regression analysis to determine the associations between conflict intensity and health outcomes.</p> Results <p>Conflict intensity was positively associated with the health outcomes included in this study. As the conflict intensity increased, the mortality and prevalence of these outcomes also increased, although this increase was not statistically significant for half the outcomes (8/16). After adjusting for the vulnerabilities and functioning of healthcare services, this positive association became significant for all health outcomes. Vulnerability and functioning of healthcare services were strong predictors of outcomes. Subgroup analysis revealed that conflict intensity was more significantly associated with outcomes in countries with high and medium vulnerability scores.</p> Conclusion <p>Existing vulnerabilities and healthcare system conditions are known to impact health outcomes. The association between conflict intensity and health outcomes strengthens when existing vulnerabilities and the state of healthcare services are considered. This underscores the importance of incorporating strategies to address socioeconomic inequities and strengthen healthcare system capacity in interventions for conflict-affected regions. This also raises additional concerns for long-term negative health effects related to the increasing trend of attacks on health care in contemporary conflicts.</p>