Background: Measles is a highly infectious virus transmitted through contact with fluids from anrninfected person's respiratory secretions. Measles causes high morbidity and mortality particularlyrnin developing countries. An average of 10-15 measles cases per year were reported in western andrnnorth western zone of Tigray region during the previous 4 years. We investigated an occurrence ofrnextended measles transmission in a remote area to confirm the existence of outbreak, identify thernetiologic agent and provide guidance on prevention and control measures. rnMethods: A descriptive study was conducted and case definition for measles was applied, arnsuspected measles case was defined as any person with fever and maculopapular rash, and cough,rnconjunctivitis, or coyrza or a patient diagnosed with measles by a clinician. From January 28- 31,rn2011 attempts were made to identify all cases by collecting a line list of cases from healthrnfacilities in the affected zones and data was analyzed by MS-Excel. Blood specimens from 5rnsuspected cases were collected in December 2010.rnResult: From October 2010 to January, 2011 a total of 408 clinically suspected cases and 16rndeaths were reported. The case fatality rate was 4%. The median age of suspected cases was 18.3rnyears (range 3 months-36 years) and 228 (56%) cases were â‰¥ 15 years of age. Three quartersrn(75%) of cases were male. The majority of cases, 352 (88%), were unvaccinated or had unknownrnvaccination status. The attack rate of 10/10,000 was highest in the western zone where 379 (93%)rncases were reported. In the North western zone there were 29 (7.1%) cases with an attack rate ofrn2/10,000. Of the 5 blood specimens collected for testing 3 (60%) were positive for measlesrnspecific IgM.rn Conclusion and recommendation: A laboratory confirmed outbreak of measles occurred over arnperiod of 5 months in primarily affecting those â‰¥15 years of age. The older age of those affected in this outbreak combined with low levels of measles immunization suggests that both routine andrnsupplementary immunization activities need strengthening Immunization campaigns may need torninclude older ages groups to improve herd immunity.