Introduction. To describe the avoided costs and to analyze the effectiveness of intravenous antibiotic treatment in continuous perfusion in patients at Hospital at Home Units (HHU) administered using elastomeric infusion pumps (EIP) prepared in a Hospital Pharmacy Service (HPS). Materials and methods. Retrospective observational study of the number and type of EIP prepared in the HPS and of the treated patients. Study period: January 2017-December2018. Analyzed data: demographic data of patients, location of infection, responsible microorganism, medication and type of EIP, dose and duration of treatment and its effectiveness in terms of cure or non-cure or patient’s death. Economic valuation considering: costs of EIP, nursing time needed for preparation and cost of HHU care. Results. A total of 1,688 EIP to treat 102 patients resulted in 106 episodes of outpatient treatment of parenteral antibiotic therapy (OPAT) for 1,409 days, thereby avoiding 1,409 days of hospital admission. A total of 59.8% of the patients were men and the mean age was 70.5 ± 17 years. A 31.1% and 68.9% of the cases were empirical and pathogen-directed treatments, respectively. The most used antimicrobials were piperacillin/tazobactam (42.7%), ceftazidime (24.5%), meropenem (19.8%), ceftolozane/tazobactam (2.8%), and cloxacillin (1.9%). Mean duration of treatment was 13.29 ± 8.60 days. Location of infection: respiratory (42.5%), urinary (17.9%), skin and soft tissue (12.3%), bacteraemia (11.3%), osteomyelitis (7.5%), abdominal (3.8%) and 4.7% in other locations. The cure rate was 84%. Total avoided cost: 580,788.28€ in the 24 months studied. Conclusion. This program represents very important economic savings for the health system, and the effectiveness of the antibiotic treatment has not been compromised.