We examined gender differences in leisure-time physical activity (LTPA) in 50 women and 28 men using questionnaire data and identified how LTPA status may be misclassified based on physical activity questionnaire content. LTPA was determined using the Four Week Physical Activity History modification of the Minnesota LTPA questionnaire. LTPA was classified as total, light- (≤ 4.0 METS), moderate- (4.5-5.5 METS), and heavy-intensity (≥ 6.0 METs), and household LTPA. The questionnaire was administered 14 times (every 26 days). Scores were computed as kcal·day−1 and min·day−1 with the 14 visits averaged to yield one year LTPA scores. Skewed data were log-transformed and are presented as the geometric mean. There were no gender differences in kcal·day−1 for total- (385 vs 421), moderate- (28.2 vs 23.3), and light-intensity LTPA (72.2 vs 52.6, p > .05). Heavy-intensity LTPA was greater in men than in women (98.1 vs 50.5, p = 0.01), while household LTPA was greater in women than in men (238.2 vs 134.7, p < .0001). Omission of heavy-intensity LTPA from the questionnaire reduced total LTI’A by 25% in men and 12% in women. In contrast, omission of household LTPA reduced total LTPA by 35% in men and 57% in women. Thus LTPA may be underestimated and activity status misclassified if questionnaires fail to include activities with high gender-specific participation rates.