Objective; This study aimed to valuate the effect of f-CNTs (functionalized carbon nanotubes) and chitosan (CS) composite on the mechanical properties and cell biocompatibility of carbonated HAp (hydroxyapatite) derived from cuttle sh bone. Methods; The microstructure characterization of carbonated HAp after hydrothermal treatment showed complete transformation into highly crystalline structure. The prepared CS/f- CNTs composite was introduced into HAp specimens under vacuum. A compressive load was applied till failure using a universal testing machine to evaluate compressive strength and elastic modulus of aragonite (CaCO3) and treated HAp with CS/f-CNTs composite. The proliferating number and percentage of MSCs (mesenchymal stem cells) in direct contact with tested materials were used as indication of cytotoxic effect after 24, 36 and 72 hours in addtion alkaline phosphatase activity (ALP) after 12 days was used as indication of osteogenic effect. Results; The HAp group with deposition of CS/f-CNTs composite showed a statistically signi cant higher compressive strength (0.82 ± 0.17 MPa) and elastic modulus (11.1 ± 1.06 MPa) and a statistically signi cant lower value for cell viability percentage (225,590 ± 8030.503, 32.95%) after 72 hours and ALP activity (85.51 ± 5.67 μU/μg protein) after 12 days of incubation. Conclusions; Carbonated HAp scaffolds reinforced with CS/f-CNTs composite can be used in low stress bonny defects.