Abstract Background Sugammadex is an alternative pharmacological drug that is capable of reversing neuromuscular blockades without the limitations that are presented by anticholinesterase drugs. Coagulation disorders that are related to treatment with sugammadex were reported. The exact mechanism of the effects on coagulation are not fully understood. Objective To evaluate the effects of rocuronium, sugammadex and the rocuronium-sugammadex complex on coagulation in an experimental model in rats. Design An experimental randomized animal study. Setting An experimental unit at the State University of São Paulo (UNESP), Botucatu, SP, Brazil. Interventions Wistar rats were randomly assigned into the following groups: the Control group; the Ssal Group – 0.5 mL of intravenous saline; the Sugammadex group – intravenous sugammadex (100 mg/kg); and the Rocuronium-Sugammadex group – intravenous solution with rocuronium (3.75 mg/kg) and sugammadex (100 mg/kg). Anaesthesia was performed by using isoflurane with controlled ventilation. Main outcome measures Coagulation factors were measured 10 minutes after the end of the preoperative preparation and 30 minutes after the administration of the drugs in accordance with the chosen groups. Results Platelet counts, prothrombin times and activated partial thromboplastin times were similar between the groups and between the moments within each group. There were reductions in the plasma fibrinogen levels between sample times 1 and 2 in the Rocuronium-Sugammadex group ( P = 0,035). Conclusion The rocuronium-sugammadex complex promoted reductions in plasma fibrinogen counts, although the levels were still within normal limits.