Purpose: The aim of this retrospective study was to analyze complications, risk factors, and corresponding treatment regarding the medial approach to harvesting tibial bone. Materials and Methods: Consecutive cases at Yokohama City University Hospital were analyzed for complications of tibial particulated bone and marrow harvesting with the medial approach. The condition of bone marrow, duration of harvesting, and complications were evaluated. The complication rate and correlations between bone marrow conditions and duration of bone harvesting were assessed. The corresponding treatments for the complication were also observed. Results: Thirty cases of tibial particulated bone and marrow harvesting for alveolar ridge or sinus floor augmentation before implant therapy from 2005 to 2014 were analyzed. Twenty-one patients had healthy bone marrow, whereas nine patients had fatty bone marrow. The duration of operation in patients who had both spontaneous pain and gait disturbance was approximately 56 minutes, which was significantly longer than that (approximately 40 minutes) in patients who had only gait disturbance (P .05). A strong correlation between fatty bone marrow condition and bone harvesting time was seen. The correlation between bone marrow condition and bone harvesting time for fatty marrow was stronger than that for healthy marrow with a trend to significant difference (P = .082). The minor and major complication rate was 96.7% and 6.6%, respectively. Two patients showed postoperative infection on the tibial harvesting site. One of them, who had fatty bone marrow, showed methicillin-resistant Staphylococcus aureus-caused osteomyelitis of the tibia, which needed to be debrided and reconstructed with vancomycin-containing bone cement. Conclusion: A duration of less than 40 minutes for harvesting time may decrease the risk of minor complications. Bone marrow condition influenced tibial bone harvesting duration, which may result in increasing the risk of complications. Regarding major complications, it was considered that wound protection was more important even if the marrow condition was healthy. Schlagwörter: bone augmentation, cancellous bone and marrow, complication, morbidity, tibial bone harvesting