BACKGROUND The aim of this cross-sectional study is to investigate gingival crevicular fluid (GCF) osteocalcin, cross-linked N-terminal telopeptide (NTx), and calprotectin levels in cyclosporin A (CsA)-induced gingival overgrowth (GO). METHODS Forty medicated patients with CsA including 20 with GO (CsA GO+), 10 without GO (CsA GO-), 10 with GO and chronic periodontitis (CsA CP) and 60 patients with CP alone, 20 patients with gingivitis, and 20 healthy patients were enrolled. Probing depth, clinical attachment level, plaque index, and papillary bleeding index were recorded. GCF calprotectin, osteocalcin, and NTx levels were analyzed by enzyme-linked immunosorbent assay. Parametric tests were used for statistical analysis. RESULTS The CsA GO+ and CP groups had significantly lower GCF osteocalcin levels and osteocalcin/NTx ratio than the healthy group, whereas GCF osteocalcin levels and osteocalcin/NTx ratio in the gingivitis group were higher than the CsA GO+, CsA GO-, CsA CP, and CP groups (P <0.05). The CP group had elevated GCF calprotectin levels compared to the other study groups (P <0.05). The CsA GO+ and CsA GO- groups also had higher GCF calprotectin levels compared to the CsA CP, gingivitis, and healthy groups (P <0.05). CONCLUSIONS Increased GCF calprotectin and decreased GCF osteocalcin levels in the CsA GO+ and CsA GO- groups might suggest that CsA plays a role on the levels of these markers. The similarity of GCF osteocalcin, NTx, and calprotectin levels in the CsA GO+ and CsA GO- groups might suggest that these molecules are not involved in the pathogenesis of GO.