Introduction: Lockdowns are designed to slow COVID-19 transmission, but they may have unanticipated relationships with other aspects of public health. Assessing the overall pattern in population health as a country implements and relaxes a lockdown is relevant, as these patterns may not necessarily be symmetric. We aimed to estimate the changing trends in cause-specific mortality in relation to the 2020 COVID-19 related lockdowns in Peru. Methods: Based on data from the Peruvian National Death Information System (SINADEF), we calculated death rates per 10 million population to assess the trends in mortality rates for non-external and external causes of death (suicides, traffic accidents, and homicides). We compared these trends to 2018-2019, before, during, and after the lockdown, stratified by sex, and adjusted by Peruvian macro-region (Lima & Callao (capital region), Coast, Highland, and Jungle). Results: Non-external deaths presented a distinctive pattern among macro-regions, with an early surge in the Jungle and a later increase in the Highland. External deaths dropped during the lockdown, however, suicides and homicides returned to previous levels in the post-lockdown period. Deaths due to traffic accidents dropped during the lockdown and returned to pre-pandemic levels by December 2020. Conclusions: We found a sudden drop in external causes of death, with suicides and homicides returning to previous levels after the lifting of the lockdown. Non-external deaths showed a differential pattern by macro-region. A close monitoring of these trends could help identify early spikes among these causes of death and take action to prevent a further increase in mortality indirectly affected by the pandemic.