With a general birth rate of 8.1? and a total fertility rate of 1.29 children per woman, Republic of Srpska can be characterised as an outstandingly low birth area. The volume of reproductive contingent represents one of the key factors of a fertility decline in a population. According to the results of the 2013 Census, the overall number of women in the thirty-five year fertility period (from 14 to 49) comprises around 22% of overall population in Republic of Srpska. Fertility differentiation by age indicates the phenomenon of delayed child bearing in which age model of reproduction prevails. In the period from 1998 to 2016, the average childbearing age when giving birth to a first child increased by 3.1 years (from 23.8 to 26.9 years). Through the analysis of fertility by the order of birth, a deficit of first-born and third-born children was identified in Republic of Srpska. In that context, a greater application of systematic measures of pro-natalist population policy is imposed as priority.