Traffic crashes with small-displacement motorcycles constitute a major health concern in motorcycle-dominant countries such as Vietnam. The purpose of this study was to improve our understanding of typical characteristics of small-displacement motorcycle crashes in Vietnam, mainly focusing on the prevalence and role of risky riding behaviours, the dangers associated with risky ridership, and the underlying motives. To that purpose, a qualitative study design was implemented, including a series of focus group discussions and in-depth interviews based on a semi-structured format with different stakeholders involved in motorcyclist safety. In terms of perceived risk, drink-riding, speeding, and inattentive riding were evaluated as the three most dangerous behaviours. The occurrence of riding under the influence of alcohol was attributed to four main underlying motives, i.e., alcohol-induced ‘false’ sense of safety, several contextual barriers preventing the adoption of safe alternatives to riding back home after having drunk, the financial cost associated with using alternative transport to return safely after drinking, and perceived unsafety of motorcycle taxi services. As for speeding, four main sub-themes emerged from the discussions as underlying motives, i.e., ‘being in a hurry’, ‘showing off’, ‘competitiveness’, and ‘thrill seeking’. Finally, inattentiveness was associated with the four following underlying motives: ‘use of mobile device’, ‘attention/search conspicuity’, ‘mind-wandering’, and ‘interaction with pillion passenger’. Overall, this suggests that risky rider behaviours are best explained as a dual process phenomenon where risk-related decisions can be under volitional control and/or guided by a reactive pathway where people demonstrate an unintentional willingness to expose themselves to danger under specific risk-conducive circumstances. Crash-prone environmental conditions for Vietnamese small-displacement motorcyclists mentioned, were heavy rain, high temperature, strong wind, dust, potholes, and other forms of pavement deterioration, as well as geometric alignment reducing intersection visibility. These findings are further translated into practical recommendations for academic researchers, policymakers, and practitioners.