OBJECTIVES: To test if the use of an inspiratory muscle training program with an electronic resistive loading device is associated with benefits as to muscle strength, weaning, and survival in the ICU. DESIGN: Prospective randomized controlled trial. SETTINGS: Study conducted at the ICU of a Navy’s hospital, Rio de Janeiro, Brazil, from January 2016 to September 2018. PATIENTS: Tracheostomized patients (18–86 yr) on prolonged weaning. INTERVENTIONS: Participants were assigned to inspiratory muscle training (intervention group) or a traditional T-piece protocol (control group). In the inspiratory muscle training group, participants underwent training with an electronic inspiratory training device (POWERbreathe K-5; Technologies Ltd, Birmingham, United Kingdom). MEASUREMENTS AND MAIN RESULTS: Changes in respiratory muscle strength and rates of ICU survival and weaning success were compared between groups. Forty-eight participants in the inspiratory muscle training group and 53 ones in the control group were included in the final analysis. The inspiratory muscle training was associated with a substantially higher gain on muscle strength as assessed by the maximal inspiratory pressure (70.5 [51.0–82.5] vs –48.0 cm H2O [36.0–72.0 cm H2O]; p = 0.003) and the timed inspiratory effort index (1.56 [1.25–2.08] vs 0.99 cm H2O/s [0.65–1.71 cm H2O/s]; p = 0.001). Outcomes at the 60th day of ICU were significantly better in the intervention group regarding both survival (71.1% vs 48.9%; p = 0.030) and weaning success (74.8% vs 44.5%; p = 0.001). CONCLUSIONS: The use of an inspiratory muscle training program with an electronic resistive loading device was associated with substantial muscle strength gain and positive impacts in two very relevant clinical outcomes: the rates of ICU survival and successful weaning.