Physical behavior changes in Parkinson's disease (PD), however, objective evidence of this is lacking. This study explored methods to objectively quantify sedentary behavior (SB) in advanced PD with the aim of identifying changes that could impact on the burden of disease. We compared the SB of 17 PD (UPDRS III 29.1 ± 5.5; disease duration 12.5 ± 6.4; H&Y (3 & 4) and 17 aged and gender matched healthy subjects. SB was measured objectively over a 7 day period using the activPAL accelerometer. SB was defined as sitting or lying and described in terms of the volume and pattern of SB. Comparison between PD and controls showed that whilst there was no difference in the volume of sedentary time (P = 0.15), there was a significant difference in distribution (P < 0.01) and pattern of accumulation of sedentary time (P < 0.01). Bouts of SB in people with PD tend to last longer than that of controls, whilst the total time spent inactive is the same for the two groups. These results suggest that PD leads to a change in the pattern of SB but not the volume. This may be interpreted as a strategy to conserve energy to maximize function. Studying the pattern of SB appears promising and has the potential to help us to understand the impact of PD and the consequences of changes in SB on the burden of disease.