Introduction Telemedicine technologies are increasingly being incorporated into infectious disease practice. We aimed to demonstrate the impact of antimicrobial stewardship through telemedicine on bacterial resistance rates. Methods We conducted a quasi-experimental study in a 220-bed hospital in southern Brazil. An antimicrobial stewardship program incorporating the use of telemedicine was implemented. Resistance and antimicrobial consumption rates were determined and analysed using a segmented regression model. Results After the intervention, the rate of appropriate antimicrobial prescription increased from 51.4% at baseline to 81.4%. Significant reductions in the consumption of fluoroquinolones (level change, β = -0.80; P < 0.01; trend change, β = -0.01; P = 0.98), first-generation cephalosporins (level change, β = -0.91; P < 0.01; trend change, β = +0.01; P = 0.96), vancomycin (level change, β = -0.47; P = 0.04; trend change, β = +0.17; P = 0.66) and polymyxins (level change, β = -0.15; P = 0.56; trend change, β = -1.75; P < 0.01) were identified. There was an increase in the consumption of amoxicillin + clavulanate (level change, β = +0.84; P < 0.01; trend change, β = +0.14; P = 0.41) and cefuroxime (level change, β = +0.21; P = 0.17; trend change, β = +0.66; P = 0.02). A significant decrease in the rate of carbapenem-resistant Acinetobacter spp. isolation (level change, β = +0.66; P = 0.01; trend change, β = -1.26; P < 0.01) was observed. Conclusions Telemedicine, which provides a tool for decision support and immediate access to experienced specialists, can promote better antibiotic selection and reductions in bacterial resistance.