Background: De Marco Formula (DMF) is a novel formulation of procaine and PVP., Objective: To assess the efficacy and safety of DMF as an adjunctive therapy for infected ischemic diabetic foot in a prospective randomized controlled clinical trial., Methods: Adult patients, 39 male/ 79 female, were randomly assigned (59 patients/treatment group) to the conventional therapy alone (A) or plus DMF (0, 15 ml/kg .day i.m.) during ten days and them twice a week until healing of the lesions or completion of 52 days (B).The response to the treatment was considered favorable when an amputation was not needed even though a decrease of the wound area or complete healing was not shown. It was considered unfavorable when a major amputation was necessary because of worsening of the lesion (wound spreading to any magnitude greater than the initial one) or the appearance of new wounds in the same leg., Results: Both groups were comparable with regard to age, sex, level of arterial occlusion, type of lesion, anatomic localization of lesions and previous surgical procedures. The cumulative percentage of unfavorable results was significantly lower after treatment B with respect to treatment A (25.4% vs. 45.8%; p= 0.02), for a reduction of 44.5%. Four slight adverse reactions were associated with DMF: vertigo and nausea at the 7th treatment administration (one patient), and headache and tachycardia at the 12th dose (another patient). Blood hemoglobin and leukocyte counts and serum alanine transaminase were not affected., Conclusion: The treatment with DMF for 52 days as an adjuvant for the conventional therapy was associated with a lower need for major amputations. It was also well tolerated and safe.