Intermittent claudication is debilitating leg pain affecting older people with peripheral arterial disease, which is improved by regular walking. This study evaluated associations between psychosocial variables and 6-min walk distance (6MWD) to identify factors that motivate walking. A total of 142 individuals with intermittent claudication (116 males; M age = 66.9 years [SD = 10.2]) completed cross-sectional assessments of sociodemographics, walking treatment beliefs and intention (Theory of Planned Behaviour), illness perceptions (Revised Illness Perceptions Questionnaire), and 6MWD. Multiple linear regression was used to evaluate relationships among psychosocial variables (treatment beliefs and illness perceptions) and outcomes (walking intention and 6MWD). Theory of planned behavior constructs were associated with intention (R = .72, p < .001) and 6MWD (R = .08, p < .001). Illness perceptions were associated with 6MWD only (R = .27, p < .001). Intention (β = 0.26), treatment control (β = −0.27), personal control (β = 0.32), coherence (β = 0.18), and risk factor attributions (β = 0.22; all ps < .05) were independently associated with 6MWD. Treatment beliefs and illness perceptions associated with intention and 6MWD in people with intermittent claudication are potential intervention targets.