Little is known about physical activity (PA) and sedentary behavior (SB) among nursing home residents although PA is known as a health promoter. This study examined PA, SB, and their predictors among nursing home residents (n = 63). Dependent variables were accelerometry-based PA and SB. Predictor variables included in a path analysis were age, sex, body mass index, Barthel Index, cognitive status (Mini-Mental State Examination), physical performance (hand grip strength and habitual walking speed), and well-being (World Health Organization-5 well-being index). PA was very low (M steps per day = 2,433) and SB was high (M percentage of sedentary time = 89.4%). PA was significantly predicted by age (β = -0.27, p = .008), body mass index (β = -0.29, p = .002), Barthel Index (β = 0.24, p = .040), and hand grip strength (β = 0.30, p = .048). SB was significantly predicted by body mass index (β = 0.27, p = .008) and Barthel Index (β = -0.30, p = .012). Results might be helpful for everyday practice to identify individuals at high risk for low PA and high SB.