In the Netherlands, educational attainment is the result of a sequence of separate educational transitions. Because of the tracked nature of the Dutch educational system, students do not make binary stay-or-leave-decisions at each transition. After having entered one track of secondary education, students can change tracks during the entire secondary course. The initial track and the secondary school outcome therefore are incongruent for a significant proportion of the Dutch students. As social background partly predicts initial track placement, track changes and successful termination of the course, we suggest distinguishing conditional and unconditional effects of family background in the transition to secondary school outcome. This paper complements findings of previous research by taking into account the tracked structure of the Dutch educational system and the entire sequence of transitions in secondary education. For the empirical analysis, repeated cross-sections from the Family Survey Dutch Population (1992, 1998, 2000 and 2003) are used. Multinomial logistic regressions reveal that inequality in the outcome of secondary education is partly explained by the fact that initial track placement is socially selective and because this initial inequality is even enhanced by track changes during secondary education. The remaining "conditional" effect of parental education, however, indicates that parental education works on top of this selection to prevent drop out. Inequality in secondary school outcome thus is a cumulative result of social background effects in a sequence of educational transitions throughout secondary education. Decreasing inequality over time is entirely explained by decreasing inequality in the transition from primary to secondary education. (Contains 2 figures, 6 tables and 7 notes.)