Over the past decades in Ukraine, the unfavorable indicators of population reproduction, the state of health of women and children, acquired in the previous period, have become persistent, one of the integrative indicators of which is the mortality of children under one year of age. The infant mortality rate is a sensitive indicator of the general sanitary and socio$economic well-being of the country, a strategic indicator of the health and survival of children, the level and quality of medical and social care, and the effectiveness of obstetric and pediatric services. Purpose — to study, analyze and determine the general and regional features of the state and dynamics of infant mortality and its components in Ukraine. Materials and methods. A retrospective analysis and assessment of the dynamics of infant mortality in Ukraine for the period 1990–2019 was carried out in the context of regions and separate states according to state and industry statistics, perinatal audit for the methodology of the WHO «MATRIX-BABIES». Methods of a systematic approach, statistical, graphic representation are applied. Results. The study found that the unfavorable demographic situation in Ukraine is accompanied by a still high, with a positive trend, the mortality rate of children in the first year of life — 12.8‰ in 1990, and 7.0‰ in 2019 (loss rate — 30.9%), a direct dependence of infant mortality rates on indicators of total fertility (r=0.340) and morbidity in children in the first year of life (r=0.888) was found with an excess of mortality under 1 year in boys compared with girls (OR with 95% CI 1.1 (1.0–1.2). Infant mortality rates are relatively low, below the average for Ukraine, in Vinnitsa, Volyn, Kyiv, Lviv, Poltava, Ternopil, Khmelnitsky regions and City Kyiv, and above average — in Dnepropetrovsk, Donetsk, Transcarpathian, Kharkiv regions. The decrease in the overall infant mortality rate was due to the positive dynamics of all its components — early neonatal (5.8‰ in 1990, 3.04‰ in 2019), neonatal (7.3‰, 4.57‰) and postneonatal mortality (5.7‰, 2.52‰, respectively) with a more intensive decrease in postneonatal mortality (rate of decline — 55.8%). However, there are doubts that the registered data on neonatal mortality, as well as on infant mortality in general, are real, since according to the perinatal audit data, the «MATRIX-BABIES» method revealed an underestimation of early neonatal mortality — an underestimation of its real level in general by 2.1–2.3 times. It is shown that the infant mortality rate has decreased from all the main causes of mortality with a more accelerated rate of decrease in infant losses from exogenous, manageable causes — respiratory diseases (rate of decline — 83.7%), infectious and parasitic diseases (rate of decline — 80.7%). At the same time, the key causes of mortality in children under 1 year of age throughout the entire observation period remain separate conditions that arise in the perinatal period (52.8–38.4 per 10,000 live births) and congenital malformations, deformities, and chromosomal abnormalities (38,6–17.2 per 10,000 live births). It was found that against the background of a decrease in infant losses in the structure of infant mortality by 43.2%, the part of mortality from certain conditions of the perinatal period increased with a significant decrease in the part of losses from exogenous causes of death — respiratory diseases by 66.7%, some infectious and parasitic diseases by 57.8%. Conclusions. In general, despite the positive dynamics of all components of infant mortality, its level characterizes a pronounced lag behind developed countries, and according to the rating of the countries of the world as of 2018, Ukraine ranks 61st among 193 countries of the world and administrative territories without state status. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of these Institutes. The informed consent of the patient was obtained for conducting the studies. No conflict of interest was declared by the authors. Key words: infant mortality, morbidity, newborns, children in the first year of life.