Background <p>Rubella virus infection is a clinically mild illness, but it can have serious effects on pregnant women, such as miscarriage, stillbirth, or congenital rubella syndrome. However, rubella is neither a notifiable disease nor part of an immunization program in Ethiopia. A suspected case of rubella has been reported in Adigrat since November 26, 2023. The study aimed to investigate and control the suspected rubella outbreak.</p> Methods <p>Following the descriptive study, a case-control study was conducted in Adigrat town from December 23, 2023, to March 30, 2024. Cases were people who presented with fever and maculopapular or laboratory-confirmed cases or epidemiologically linked with the confirmed person, and controls were neighbours to a case with no signs and symptoms of rubella. Cases were selected using simple random sampling, and controls were the two closest neighbours per case. Data was collected using a semi-structured questionnaire and analysed with SPSS version 27. Logistic regression was used to determine the association of illness with risk factors, and the results were tested using OR, a 95% confidence interval.</p> Result <p>A total of 350 cases of rubella were identified with an attack rate of 3.16/1000. The attack rate was high in children aged five to nine years (11/1000) and in kebelle 04 (8/1000). Five out of seven samples were tested positive for rubella-specific IgM antibodies. Having contact in a school setting (AOR = 7.063: 95% CI = 3.269–15.256), having household contact (AOR = 6.551:95%CI = 2.534–16.941) and ≥ 5 family size (AOR = 2.312:95%CI = 1.090–4.907) were significantly associated with rubella.</p> Conclusion <p>The overall attack rate of the rubella outbreak was high, with a predominance of children under fifteen. Large family size, and having contact with infected individuals, were contributing factors for contracting rubella. Rubella vaccine should be considered to prevent similar outbreaks.</p>