In order to assess the impact of COVID-19 on the safety of pedestrians in Poland, a time-series model of a monthly number of killed and seriously injured (KSI) pedestrians was formulated. According to the calibrated model, the monthly KSI number was dependent on the average traffic volume index, which was a measure of exposure, presence of Covid restrictions and seasonality factors. KSI was significantly higher during autumn and winter months due mostly to longer periods of darkness during the day. Covid restrictions caused a drop of this number by 22.9%. In addition, during the lockdown periods, there was a 28.6% drop in average reference traffic volumes, which translates into an additional decrease in pedestrian casualties by 41.4%. The overall impact of Covid restrictions could amount to as much as 54.8%. Although during Covid restriction periods the overall number of accidents decreased, there was a marked increase in the mortality rate. A new safety indicator, called “Monthly Average Daily Deaths” is proposed at unsignalized pedestrian crossings which can express the overall safety trend as well as seasonal variations of the safety situation. The overall trend is decreasing the number of killed pedestrians by around 11% per year on average. The authors anticipate that the conclusions presented in the article will make it possible to distinguish the impact of various factors (such as the pandemic, changes in regulations, etc.) in the future analyses related to improving road safety.