The present study investigates the release of cardiac troponin-I (cTnI) as a biomarker of cardiac injuries induced by doxorubicin (Doxo) alone and along with ciprofloxacin (Cipro), following acute and chronic dose protocol in Sprague Dawley rats. In chronic protocol, rats were given multiple intra-peritoneal (i.p) injections of Doxo (1 or 2.5 mg kg(-1)) alone or in combination with Cipro (20 mg kg(-1) daily) and a placebo control. Whereas in acute protocol, rats were subjected to receive single i.p. injection of Doxo (6 or 15 mg kg(-1)) alone or along with Cipro (20 mg kg(-1)) and placebo treatment with saline (control). The plasma levels of cTnI were measured by using Enzyme-linked Immuno Sorbent Assay (ELISA) technique. All the treated groups, following acute or chronic dose protocol showed significant increase in cTnI plasma level from 137-248% in comparison to control (p<0.0001). The cTnI plasma levels increased in dose dependent manner after following acute and chronic dose protocol. The difference between two doses following chronic (1 mg kg(-1) vs. 2.5 mg kg(-1)) and acute (6 vs. 15 mg kg(-1)) administration was 34.6 and 31.5%, respectively. Results of this investigation suggest that Doxo alone and in combination with Cipro from both the chronic and acute groups showed cardio-toxicity (release of cTnI). To our knowledge this is the first description towards Doxo-Cipro is induced cardiotoxicity and could be a bridge between preclinical and clinical practice for physicians in making an expert opinion dealing with above mentioned group.