Purpose: To prospectively evaluate the survival at 1 and 4 years of short implants retaining removable partial dentures (RPDs) in Kennedy Class I and II edentulism. Materials and Methods: Twenty patients (Kennedy Class I and II) rehabilitated with RPDs were selected for the insertion of one short implant in the distal edentulous ridge, connected to the RPD with a Locator attachment after osseointegration. The following data were recorded at the 1- and 4-year follow-up: bone loss, bleeding on probing (BOP), probing depth (PD), implant mobility, and survival. Results: Thirty-five implants were placed from September 2012 to April 2014. At the 4-year follow-up, 12 implants showed BOP, and for PD, 15 implants showed 2 mm, 16 implants showed 3 mm, and 2 implants showed 4 mm. One implant showed mobility, and two were lost (survival rate: 94.3%; 95% CI: 80.84 to 99.30). The mean bone loss was 1.04 ± 1.88 mm. Conclusion: Within the limitations of this study, the implant survival rate and the mean bone loss values reported are comparable with those reported by other authors. The use of short implants for retaining RPDs may be considered a viable treatment option for patients with distal edentulism and contraindications for more complex implant rehabilitation. Palabras clave: bone loss, implant survival rate, removable partial denture, short implants