Background Clinicians and public health professionals are centrally concerned with mediating risk. However, people often resist the risk-related information that is communicated to them by experts, or have their own models of risk that conflict with expert views. Quantitative studies have clearly demonstrated the importance of health beliefs and various cognitive and emotional processes in shaping risk perception. More recently, a growing body of qualitative research has emerged, exploring lay conceptualizations, experiences and constructions of cancer risk. To date, this literature has not been synthesized. Objective We report the findings of a synthesis of qualitative literature regarding the ways in which lay people construct and experience cancer risk. Design We identified 87 articles and used the method of 'thematic synthesis' to identify and interpret key concepts from existing studies. Results Eight analytic categories were developed: (i) perceptions of risk factors; (ii) process of risk perception; (iii) seeking control and taking responsibility (motivational factors); (iv) experiencing cancer directly; (v) constructing risk temporally; (vi) embodying risk; (vii) identifying with risk; and (viii) constructing risk in a social context. Conclusions Qualitative enquiry can provide us with a rich and nuanced picture of the ways in which people understand, experience and construct risk and how being 'at risk' is managed, and can assist us in our communication with both individual patients and populations.