Purpose: This paper aims to examine whether greater consideration should be given to the timing of sexual health interventions within the calendar year. Design/methodology/approach: The paper uses a review of the literature. Findings: The evidence points to seasonality in a number of areas of sexual health among young people, including: the timing of first intercourse and conceptions, both of which peak in the summer and over Christmas; abortions which peak approximately two months later in February and late summer and sexually transmitted infections, which peak over the summer and autumn. In the case of conceptions there is evidence that the seasonal pattern among young people is different from that of adults. Potential explanations fall into four main categories: biological; behavioural; social, and service-related. Research limitations/implications: Many of the studies included in this review are from the USA, and some are based on either small samples or specific risk groups, which raises questions of representativeness and generalisability. Further, it is notable how little research there has been regarding seasonal variations in other aspects of sexual behaviour, such as risk reduction practice and other potential explanatory factors such as health-seeking behaviour and availability of services. Practical implications: The findings consistently point to periods of heightened sexual activity among young people in the summer and over Christmas, and suggest that greater consideration should indeed be given to the timing of sexual health interventions within the calendar year. Originality/value: To the best of the authors' knowledge, no other review of this kind has yet been found. (Contains 1 table.)