OBJECTIVE: To evaluate the impact of indirect cost (due to absence from work, disability, mortality) in economic evaluations comparing minimally invasive procedures using devices to conventional open surgery. Indirect cost savings benefit patients, employers and society as a whole and therefore are important costs to consider. METHODS: We searched the literature and identified studies in which “indirect cost”, “convalescence” or “work loss” were included in the analysis. All articles published since 1990 on menorrhagia (laparoscopic hysterectomy/endometrial ablation versus open hysterectomy), Gastroesophageal Reflux Disease (GERD) (laparoscopic versus open Nissen fundoplication), and coronary artery disease (Percutaneous Transluminal Coronary Angioplasty (PTCA) versus Coronary Artery Bypass Graft (CABG) surgery) were reviewed. Key information abstracted included: days of work lost, direct and indirect cost estimates, costing methodology, and follow-up period. The percentage impact, measured as the change in the difference between the total cost of open surgery compared to the less-invasive procedure due to the inclusion of indirect cost, was calculated. RESULTS: The review produced 11 articles on menorrhagia, 5 on GERD, and 5 on coronary artery disease. There were large differences in the average days of work loss between open surgery and less-invasive procedures; 21 days for laparoscopic versus 40 days for open hysterectomy, 15 days for laparoscopic versus 35 days for open fundoplication, and 27 days for PTCA versus 74 days for CABG. The percentage impact or difference in total cost due to the inclusion of indirect cost was on average 32.8% (4.4% - 69.4%). CONCLUSIONS: Cost savings associated with minimally invasive surgery compared to open surgery are significantly increased when indirect costs are included in the assessment. Future economic outcome studies should attempt to include indirect cost measures to fully capture the benefits of devices and minimally invasive procedures.