This study compares a miniaturized, portable, sequential, pneumatic compression device (ActiveCare continuous enhanced circulation therapy [CECT] system) (Medical Compression Systems Ltd, Or Aqiva, Israel), with a nonmobile, nonsequential device on the ability to prevent postoperative deep venous thrombosis (DVT) after joint arthroplasty. All patients were treated with low-molecular-weight heparin, application of 1 of the 2 devices perioperatively, and routine duplex screening. The CECT system had better compliance (83% of the time vs 49%), lower rates of DVT (1.3% compared with 3.6%), reduction in clinically important pulmonary embolism (0 compared to 0.66%), and shorter length of hospital stay (4.2 vs. 5.0 days). The portable CECT system proved significantly more effective than the standard intermittent pneumatic compression when used in conjunction with low-molecular-weight heparin for DVT prevention in high-risk orthopedic patients.