The distributions of geomagnetic activity levels and the number of emergency ambulance calls by days of the lunar (synodic) month were mapped. The input for the study was Kp index data and the anonymized catalog of ambulance calls to the Petrozavodsk Emergency Care Hospital in 2015–2017. The data were processed using the superposed epochs method and the clustering and trend isolation algorithms. High daily Kp indexes are mainly grouped around new moon while low Kp indexes – near full moon. The distributions of the number of emergency calls for cardiovascular diseases, mental disorders, and neuropathies have their specific features. Possible causes of lunar cycle-related effects of geomagnetic activity and the peculiarities of emergency ambulance calls distributions are discussed.