Background Little is known about the health-risk behaviours of young people in the Middle East, particularly the occupied Palestinian territory (oPt). Our aim in this study was to gain insights into the prevalence and patterns of risk-taking behaviours of Palestinian youth. Methods We organised ten focus groups and 17 in-depth interviews with young people (aged 16–24 years) as part of the formative phase of a cross-sectional representative study of risk behaviours in the West Bank, including East Jerusalem, oPt, in 2012. A combination of purposive and convenience sampling was used to select the sample, with representation of male and female young people from different localities in the region (urban, rural, refugee camps). The non-probability sample was balanced across these categories, but the people whom we interviewed might not be representative of the overall young Palestinian population. NVivo (version 9) was used for the qualitative analysis. RAND Corporation, Santa Monica, CA, USA, approved the study protocol in January, 2012. We obtained informed verbal consent from participants aged 18 years and older, and assent from participants younger than 18 years and their parents. Findings 83 individuals (42 male and 41 female; mean age 20·0 years [SD 2·2]) participated in the study. Participants reported that substance use and sexual activity outside marriage were common, even in conservative communities. Use of drugs, the most common of which were hashish and marijuana, was perceived to be especially prevalent in refugee camps and in East Jerusalem. The most commonly reported types of sexual activity were oral and anal intercourse. Vaginal intercourse was less common than were other types of sexual intercourse outside marriage. Some young people had sexual intercourse with sex workers; they went to brothels in the West Bank, including East Jerusalem, and in Israel. Most respondents were of the opinion that young people did not usually use protection during sexual intercourse. Interpretation To the best of our knowledge, this is the first study of the health-risk behaviours of young Palestinian people. By contrast with the conservative social context in the oPt, the findings suggest that drug use and unprotected sexual intercourse outside marriage might be more common than is currently assumed. These results might be perceived as indicating surprisingly high rates of sexual and other risky behaviours; however, we cannot exclude the possibility that participants might have overstated or understated drug use and sexual behaviours, but this possibility is unlikely to be a major concern for focus groups discussing young people in general and for participants who are of the opinion that there is a high prevalence of these behaviours. Health-risk behaviours in the oPt are a concern because of the low awareness of the potential health consequences. The results draw attention to the need to include sexual reproductive health on the national agenda and ensure that it is included in the programmes of national institutions. The formative findings from this study will be used to further explore the issues in a larger representative sample to improve understanding of prevalence, patterns, and causes of risk-taking behaviours. Funding National Institutes of Health, Bethesda, MD, USA.