Measles virus, an RNA virus of the genus Morbillivirus in the family Paramyxoviridae, is the etiological agent of measles disease, the fifth worldwide cause of death in children < 5 years of age. Despite the ongoing immunization progress in Nigeria, several sporadic cases and outbreaks of measles are still being reported annually, even among the immunized in the country. Continuous surveillance and early detection by laboratory diagnosis is of importance for early management of cases and prompt containment of community spread. Reverse Transcription Polymerase Chain Reaction (RT-PCR) testing was used for prompt diagnosis of all febrile rash illness (FRI) cases captured during routine disease surveillance activities in selected Health Facilities in Lagos State from 2016 to 2018. Whole blood or throat swab samples were collected and screened by RT-PCR from 140 consenting FRI patients accessing selected health facilities in Lagos State, Nigeria. Nine (6.4%) out of the 140 samples screened by RT-PCR were positive for Measles RNA. All the 9 measles positive cases were from children ages 1 – 5 years with females being more infected than males in ratio 3:1, although without any statistical significance (p= 0.7735). Out of eight Local Government Areas (LGAs) where FRI cases were sampled, only two of them (Eti-Osa and Lagos Mainland LGAs) account for the nine measles positive cases detected in this work. It is however a possibility that the number of LGAs with positive measles cases could have been more than two if all health facilities in the sampled LGAs were selected for the work, but within the limit of available resources, all health facilities could not be sampled.