Many investigations of children's rights and child development in Bulgaria have not addressed the overall deterioration of the social environment that may have disproportionately affected children. This paper investigates the changes that occurred in Bulgaria over the past decade of transition from a totalitarian government to a democracy in three dimensions of child welfare recognized as fundamental child rights: economic well-being, health, and education. The analysis of child welfare relies primarily on statistical data gathered annually. The paper also focuses on particularly vulnerable groups of children, those born of teenage and single mothers and those living in institutions. Findings indicate that the decline in real income over the past decade has been large for all family types and particularly severe for families with several children. The deterioration in child economic well-being has been accompanied by a worsening in indicators of children's health, including infant mortality and child morbidity. The preschool enrollment rate has almost reached its pre-transition level in the late 1990s. Although the teen fertility rate fell in the 1990s, it is still high, and the share of births to unmarried mothers has risen dramatically. The rate of placement in infant homes and orphanages increased during the transition at the same time that living conditions in these institutions deteriorated sharply. The paper concludes with recommendations for public policy. (Contains 23 figures, 14 appended tables, and 63 references.) (KB)