Very little is known about the cognitive functioning of people with body-focused repetitive behaviours and the few existing studies provide mixed findings. The aim of this study was to investigate the interplay between attentional control, negative affectivity, and focused skin picking. We hypothesized that the control of attention is associated with focused style of skin picking and that this relationship is moderated by negative affectivity. The final sample consisted of 273 non-clinical subjects (79% women) aged 18 to 54 years; study variables were assessed using questionnaires. Moderation analysis was conducted, followed by a simple slope analysis, and the Johnson-Neyman technique was used to probe the interaction effect. We found that at the low level of negative affectivity, the relationship between attentional control and focused skin picking is negative, but not at the higher levels of this trait. Interestingly, when negative affectivity reaches very high intensity, the association between attentional control and skin picking becomes positive. This relationship seems to be quite complex and may depend on the way that cognitive abilities are used by the individual, as well as on the stage of cognitive processing that they are applied to. Further studies using behavioural measures of attention are needed to better understand this issue.