Aims: To describe outcome expectations related to delayed sexual transition, to examine the dimensionality and internal consistency of such expectations, and to examine variations in social outcome expectations across subgroups defined by demographic variables, indicators of socioeconomic status and predictors related to school and educational ambitions. Methods: Data stem from a survey among school students (grades 8-12) in Mankweng, Limpopo, South Africa (n=5,697). A five-item scale of outcome expectations was analysed with frequency and percentage distributions, principal components analysis, Cronbach's alpha, and general linear model procedures, while controlling for the cluster nature of the sample (school classes). Results: Four items formed a component on negative social outcome expectations (SOE) related to delayed sexual transition. The internal consistency of the SOE scale proved adequate. Negative SOEs increased with age, were higher among males than females, and decreased with father's education. Negative expectations were high among students who had repeated a school year due to failing exams, among those who did not expect to complete schooling up until grade 12, and among students who reported absence from school. Discussion: Negative social outcome expectations related to delayed sexual transition have elsewhere been shown to be important in predicting actual transition. The present study shows that there is considerable room for positive changes in such expectations. Negative SOEs may contribute to explaining demographic and socioeconomic variations in sexual transition. Conclusions: Social outcome expectations deserve more attention in programmes aimed at promoting sexual- and reproductive health.