AIM To compare, clinically and radiographically, short dental implants (6mm) to long implants (11-15 mm) placed with sinus grafting. METHODS Participants with 5-7 mm of bone height in the posterior maxilla were randomly allocated to receive short implants (GS) or long implants with sinus grafting (GG). Implants were loaded with single crowns 6 months after placement (PR). Patients were re-evaluated 12 months after loading (FU-1). Outcome variables included: Implant survival rate (CSR), marginal bone level alteration (MBL), periodontal probing depth (PPD), bleeding on probing (BoP), plaque control record (PCR) and crown-to-implant ratios (C/I). Statistical analysis was performed using non-parametric tests. RESULTS In 97 subjects, 132 implants were re-evaluated at FU-1. The CSR was 100%. The MBL from implant placement (IP) to (PR) was -0.22±0.4mm for GG and -0.3±0.45mm for GS (p<0.001). MBL from IP to FU-1 was -0.37±0.59mm for GG and -0.22±0.3mm for GS (p<0.001). Intergroup comparisons showed non significant differences for MBL (p>0.05), PPD (p=1) and PCR (p=0.09). BoP was higher in the GS (p=0.04). The C/I was 0.99 ±0.17 for GG and 1.86 ± 0.23 for GS (p<0.001). No correlation was observed between C/I and MBL, (GG: p=0.13; GS: p=0.38). CONCLUSIONS Both treatment modalities provided similar outcomes. This article is protected by copyright. All rights reserved.