Backgroud: To investigate the safety and efficacy of tacrolimus in patients with connective tissue disease associated interstitial lung disease(CTD-ILD)in clinical practice.Methods: We retrospectively studied 13 patients diagnosed with CTD-ILD,treated with tacrolimus(2mg/d)and corticosteroids with or without cyclophosphamide.Demographic data,laboratory assessment,lung function,radiographic images were reviewed.Corticosteroid dose and adverse events were also evaluated.Results: Thirteen CTD-ILD patients including 3 dermatomyositis(DM),2 clinically amyopathic dermatomyositis(CADM),4 rheumatoidarthritis(RA),3 Sj(o)grens syndrome(SS),1 anca associated vasculitis(ANCA).One of ADM and RA patients received tacrolimus and cyclophosphamide.We observed a median significant improvement of 10.8%in forced vital capacity(from a median baseline of 43%; range 35–55%; p=0.03),in the 6–12 months following treatment with tacrolimus.The serum ferritin level declined significantly(720.3±54.38ng/ml VS 239.6±39.45ng/ml,p<0.05)after treatment.Chest HRCT scans after the administration of tacrolimus showed the lung ground-glass opacities were almost resolved after the 3-6 months of tacrolimus administration.A statistically significant reduction in the corticosteroid dosage was also observed.There were no side effects other than moderate hypertension,aggravation of diabetes mellitus and dysfunction of liver.Conclusion: Tacrolimus is a well-tolerated and effective therapy for connective tissue disease associated interstitial lung disease patients.