BACKGROUND: Guidelines recommend reducing treatment in patients with well-controlled asthma after 3 months of stability. However, there is inadequate real-life data to guide physicians on therapy change in daily practice. OBJECTIVE: To assess asthma control after change to and step-down of fluticasone propionate/formoterol fumarate dihydrate (FP/FOR) in real-life patients. METHODS: In a randomized controlled, pragmatic, open-label trial, 225 well-controlled patients with asthma were randomized (1:2) to maintain high-dose fluticasone propionate/salmeterol xinafoate (FP/SAL, 1000/100 μg) or switch to FP/FOR (1000/40 μg) daily for 12 weeks (phase 1). One hundred sixteen patients stable on FP/FOR at week 12 were subsequently randomized (1:1) to maintain this therapy, or stepped down to FP/FOR (500/20 μg) daily for 12 weeks (phase 2). The primary end point was the 7-question Asthma Control Questionnaire (ACQ7) score. RESULTS: In phase 1, FP/FOR (1000/40 μg) (n = 126) was noninferior to FP/SAL (1000/100 μg) (n = 73) for ACQ7 (difference in means, -0.12; 95% CI, -0.32 to 0.09). In phase 2, FP/FOR (500/20 μg) (n = 52) was noninferior to FP/FOR (1000/40 μg) (n = 52) for ACQ7 (difference in means, 0.01; 95% CI, -0.20 to 0.22). There was no significant difference in exacerbation rate between the groups in either phase. However, 1 to 2 exacerbations in 12 months before phase 1 were associated with the occurrence of an exacerbation after step-down (P = .007). CONCLUSIONS: In patients with well-controlled asthma, a change from FP/SAL to FP/FOR did not compromise asthma control. Step-down of FP/FOR was well tolerated; however, in contrast to current guidelines, our data suggest caution in stepping down patients uncontrolled in the last 12 months. Larger step-down studies are required to confirm these findings.