OBJECTIVE: To perform a cost-effectiveness analysis of a multifactorial, tailored intervention to reduce falls among a heterogeneous group of high-risk elderly people. DESIGN: Randomized control trial. SETTINGS: Communities. PARTICIPANTS: Adults aged at least 65 years (N=354) seen at the emergency department (ED) for a fall or fall-related injury and discharged home. INTERVENTIONS: The intervention group received a tailored program of physical therapy focused on progressive training in strength, balance, and gait for a period of 3 months. They also received screening and referrals for low vision, polypharmacy, and environmental hazards. The Short Physical Performance Battery (SPPB) test was assessed at regular intervals to allocate participants into either a home-based or group center-based program. The control group received usual care prescribed by a physician and educational materials on falls prevention. MAIN OUTCOME MEASURES: The incremental cost-effectiveness ratio (ICER) over the 9-month study period based on intervention costs and utility in terms of quality-adjusted life years (QALYs) calculated from EuroQol-5D scores. RESULTS: The ICER was 120,667 Singapore dollars (S$) per QALY gained (S$362/0.003 QALYs), above benchmark values (S$70,000). However, the intervention was more effective and cost-saving among those with SPPB scores of greater than 6 at baseline, higher cognitive function, better vision and no more than 1 fall in the preceding 6 months. The intervention was also cost-effective among those with 0-1 critical comorbidities (S$22,646/QALY). CONCLUSION: The intervention was, overall, not cost-effective, compared to usual care. However, the program was cost-effective among healthier subgroups, and even potentially cost-saving among individuals with sufficient reserve to benefit.