Frequent deaths of children deeply influenced the general death rate in the past. The curve of infant mortality nearly created the curve of general mortality, because very many new-borns died during the first year of life. This was affected by the standard of breastfeeding in a given society, so the rate of infant mortality was markedly different locally. The infant mortality in towns of Frydek and Mistek kept above 500 per mille until the mid-19th century and it droped below this limit as late as the second half of the 19th century, though slightly. In Frydek, the perinatal mortality was lower, but the foetal mortality was higher than in Mistek. Causes of deaths were taken into account too, nevertheless only within the classification of diseases used at that time, it means especially the rate of various accidents, including abortions, the extent of influence that infectious diseases and avitaminosis exerted on the death rate.