INTRODUCTION: As of March 23, 2020, suspension of non-essential activities was declared in Mexico throughout the country in order to mitigate the spread of the COVID-19 pandemic. OBJECTIVE: To analyze data on the first 1,510 laboratory-confirmed cases of COVID-19 in Mexico, and to describe the geographical distribution of the disease and its transmission dynamics. METHOD: Description of the first COVID-19 cases with real-time RT-PCR-positive test, as well as evaluation of epidemiological measures, cumulative incidence, rate of transmission, and mortality and lethality rates during the first month of the epidemic. RESULTS: Average age was 43 years, and 58 % were males; 44 % of initial cases were imported. Lethality in the population during the first month went from 1.08 to 3.97 per 100 cases; however, the trend is linear and similar to that observed in Europe. CONCLUSIONS: In Mexico, social distancing is being applied, but studies are still required on the dynamics of the epidemic, person-to-person transmission, incidence of subclinical infections, and patient survival.