Background: Despite the availability of an effective vaccine, measles outbreaks continue to occur. According to the World Health Organization (WHO), a confirmed outbreak of measles is defined as if any 3 or more of blood specimens collected from a local government area (LGA) and within one month, having reached the laboratory in good condition, is IgM positive. This paper describes the outbreak investigation in two rural communities in a southwestern state in Nigeria.Methods: This was a descriptive cross-sectional study design. The outbreak investigation was conducted by a team of multi-disciplinary experts. Detailed case investigation of index cases, active case finding, vaccination coverage surveys and social mobilization activities were carried out. Descriptive analysis was using Microsoft excel and quantum geographic information system (GIS) was used to represent cases geographically.Results: A total of 42 measles cases were detected based on the WHO measles case definition. Blood samples were collected from 12 of the suspected cases for IgM determination, out of which 7 cases were IgM+. Majority of cases were <5 years old. Sixty-nine percent of the cases had received Measles vaccine. Socio-cultural and traditional beliefs were not unconnected to the poor uptake of vaccination.Conclusions: We confirmed the occurrence of measles outbreaks in Akotogbo and Ala-Elefosu communities, in Ondo State. Both communities had suboptimal measles vaccination coverages, highlighting the need to strengthen routine immunization (RI) services but also immediately addressing the sociocultural factors responsible for poor health seeking behavior and utilization of RI and primary health care (PHC) services.