OBJECTIVE: to describe a COVID-19 cluster and the strategies used to contain the virus, in a municipality in the interior region of Mato Grosso state, Brazil. METHODS: this is a descriptive study of documental records of an epidemiological investigation conducted in April 2020. RESULTS: introduction of SARS-CoV-2 in the municipality was identified through a cluster comprised of five people, 4 were symptomatic and 1 was asymptomatic, after the virus was imported by index cases C01 and C02; in addition to household transmission (C03, C04), a physiotherapist (C05) was infected through contact with C02; with the exception of C04, all had an influenza-like symptoms and C02 required hospitalization; as for laboratory tests, all were seroreactive and C01 was RT-PCR positive. CONCLUSION: dissemination of COVID-19 was contained by effective home isolation, an important instrument that should be adopted early by unaffected municipalities to contain virus dissemination, as well as by serological testing that detected infection in asymptomatic patients.