Motor fluctuations (MF) are important determinants of quality of life in Parkinson's disease (PD). To determine whether the Personal Kineti Graph (PKG), a wearable motion tracking device, can define MF progression, we correlated PKG fluctuator scores (FS) with clinical motor fluctuator profiles in a case-control cohort study. 54 subjects completed a 6-day PKG trial and completed a standardized motor diary. We distinguished non-fluctuators (NF), early (EF), moderate (MF) and troublesome fluctuators (TF), based on Wearing Off Questionnaire and Movement Disorders Society-Unified Parkinson's Disease Rating Scale scores. PKG FS significantly differentiated EF and TF, as well as dyskinetic and non-dyskinetic subjects. Motor diaries could not distinguish the four study groups on the basis of average OFF time, while average time with dyskinesia distinguished NF and MF. In conclusion, PKG FS can distinguish EF from TF, as well as dyskinetic from non-dyskinetic patients, but cannot discriminate subtler MF. PKG may provide objective MF measures for routine PD management and clinical trials.