BACKGROUND The results from reports analyzing the occurrence of gingival overgrowth (GO) induced by tacrolimus are controversial. In addition, the role of pharmacological and periodontal variables on the development and severity of GO have not been well-established. Therefore, the aim of the present study was to determine the effect of potential risk variables for GO in a Brazilian population comprising renal transplant recipients medicated with tacrolimus in the absence of calcium channel blockers. MATERIALS AND METHODS Demographic, pharmacological, and periodontal data, recorded from 125 subjects selected to participate in the study, was analyzed with the use of the independent sample t test, the chi-squared statistic, or Mann-Whitney test. The effects of risk variables on GO scores were subsequently examined using multivariate regression analysis and general linear model. RESULTS The prevalence of clinically significant GO (> or =30%) in the study population was of 7.25%. These subjects showed greater averages of plaque scores (P=0.0043) as well as papillary bleeding index (P=0.0026) when compared to subjects with GO <30%. Papillary bleeding index, time since transplant and azathioprine dosage were significant in the univariate and multivariate models (adjusted R=43.8%), whereas plaque index was significant only in the univariate model. CONCLUSIONS This study revealed that, in the absence of calcium channel blockers, gingival inflammation, represented by the papillary bleeding index, was a variable associated with Tcr-induced GO, indicating the importance of periodontal maintenance of subjects under Tcr immunosuppressive regimens.