Purpose: To compare the efficacy of immediate functionally loaded implants placed with a flapless procedure (test group) versus implants placed after flap elevation and conventional load-free healing (control group) in partially edentulous patients. Materials and Methods: Forty patients were randomized: 20 to the flapless immediately loaded group and 20 to the conventional group. To be immediately loaded, implants had to be inserted with a minimum torque > 45 Ncm. Implants in the immediately loaded group were provided with full acrylic resin temporary restorations the same day. Implants in the conventional group were submerged (anterior region) or left unsubmerged (posterior region) and were left load-free for 3 months (mandibles) or 4 months (maxillae). Provisional restorations were replaced with definitive single metal-ceramic crowns 1 month postloading. Outcome measures were prosthesis and implant failures, biological and prosthetic complications, postoperative edema, pain, and use of analgesics. Independent sample x2 tests, Mann-Whitney tests, t tests, and paired t tests were used with a significance level of .05. Results: Fifty-two implants were placed in the flapless group and 56 in the conventionally loaded group. In the flapless group, 1 flap had to be raised to control the direction of the bur and 1 implant did not reach the planned primary stability and was treated as belonging to the conventional group. After 3 years no dropouts or failures occurred. There was no statistically significant difference for complications; however, patients in the conventional group had significantly more postoperative edema and pain and consumed more analgesics than those in the flapless group. Osstell values were significantly higher at baseline in the flapless group (P = .033). When comparing baseline data with years 1, 2, and 3 within each group, mean Osstell values of the flapless group did not increase, whereas there were statistically significant increases in the Periotest values. Conclusions: Implants can be successfully placed flapless and loaded immediately without compromising success rates; the procedure decreases treatment time and patient discomfort. Palabras clave: dental implants, flapless, immediate loading, partial edentulism, randomized controlled clinical trial