Introduction: Heatwave can increase the risk for heat-related illnesses and mortality. Many studies showed certain population are vulnerable to heatwave such as elderly, children and low-income households. However, the findings were inconsistent. Therefore, this systematic review provides a comprehensive review on heatwave impact and vulnerability factors on the mortality and morbidity impacts. Methodology: Five electronic databases (Pubmed, Ebsco Host, WOS, OVID Medline and Scopus) were primary searching tools to retrieve relevant literatures. This systematic review used the Medical Subject Heading (MESH) terms and keywords. An additional searching tool (Google Scholar) was used to seek further information and minimize missed evidence. We selected the literature based on the inclusion criteria (empirical full-text article, English language and published between 2010-2021). Two authors were assigned in each step of the process, starting from screening of the title, abstract and full text based on the inclusion criteria, data extraction and quality appraisal. Mixed-Method Appraisal Tool (MMAT) was utilized to assess the quality of selected articles. Thematic analysis and narrative approach were used to describe the findings. Conclusion This review presents the comprehensive evidence-based regarding heatwave impact and associated vulnerable groups for better understanding and effective preventive measure planning to reduce the impact of heatwave on population health.