The dataset consists of twenty-nine years of continuous monthly capture-mark-recapture entries on a 3ha mosaic field (MOSA) in Morogoro, Tanzania. It is one of the most accurate and long-running (capture-recapture time series on a small mammal species worldwide and unique to Africa. From March 1994 until February 2023, the total dataset consisted of 49216 captures of 21927 unique individual rodents. The database is uploaded on Github and can be used by researchers to test hypotheses on the population dynamics of small mammals (e.g. to test the effect of climate change) or to validate new algorithms on real long-term field data (e.g. new survival analyses techniques). It is also useful for both scientists and decision-makers who want to optimize rodent control strategies and predict outbreaks of multimammate mice or the pathogens they carry (e.g. Lassa virus).