Objective: In the previous decade, several reports have been published regarding implants inserted in autografts, but none have analyzed implants inserted in fresh-frozen bone allografts. Thus, a retrospective study was planned to verify if 4-months' delay from grafting to implant insertion is a safe period before prosthetic rehabilitation of implants placed in fresh-frozen bone allografts. Method and Materials: Between December 2003 and December 2006, 22 patients (10 women and 12 men with a median age of 51 years) underwent grafting with horizontal augmentation without membrane and 88 implants inserted thereafter. The mean implant follow-up was 27 months. Implants used were 30 double etched (3i, Osseotite, Biomet), 10 SLA1 (Astratech), 26 anodic oxidized (Nobel Biocare), 12 CaPO4 ceramic-blasted (Lifecore Biomedical), 7 SLA2 (Sweden & Martina Spa), 2 ITI (Straumann), and 1 Biotec (Povolaro di Dueville). Implant diameter and length ranged from 3.25 to 5.0 mm and from 8.0 to 15.0 mm, respectively. Implants were inserted to replace 10 incisors, 7 canines, 36 premolars, and 35 molars. Results: No implants were lost (ie, survival rate = 100%). No difference was detected when comparing implants loaded after 4 months versus those loaded after 6 or more months (209 implants). Conclusion: Four-months' delay from grafting to implant insertion is a safe period to obtain a high survival rate and success rate for implants inserted in fresh-frozen bone. Keywords: allograft, Cox regression, homograft, iliac crest, implant, Kaplan-Meier algorithm