Purpose: To evaluate a new cultivated coral graft (CCG) in an in vivo experimental guided bone regeneration (GBR) procedure. Materials and Methods: The calvarias of eight rabbits were surgically exposed, and circular defects 8 mm in diameter were prepared. One defect was filled with CCG particles (experimental group); the contralateral defect (control group) was spontaneously filled by blood clot. All defects were covered with a collagen membrane. Subjects were euthanized after 8 weeks. Results: Histologic observations of the defects showed similar bone growth patterns in both experimental and control osteotomies. In the experimental defects, no traces of coral particles were observed. Histometric analysis showed denser bone in the pristine zone (65%–66%) than in the peripheral zone for both the control (50%) and experimental defects (31%) (P = not significant). The new bone percentage was reduced from the peripheral zone toward the middle and the center of the defect (31%, 32%, and 27%, respectively) as the distance from the peripheral pristine bone borders increased. Conclusions: The existing data supports the complete degradation of CCG as a spacemaintaining scaffold for GBR procedures.