Background: People living with HIV (PLHIV) experience balance impairments due to neuropathy, muscle weakness, and central nervous system alterations, which increase fall risk. While most studies focus on level walking, there is limited information about motor control adaptation during gait on inclined surfaces. Objective: To determine whether postural sway while walking differs between PLHIV at risk of falls and those not at risk during flat and inclined surfaces. Methods: Thirty-two PLHIV (21 fall risk; 11 non–fall risk) completed walking trials at 0% and 8% incline. The Activities-specific Balance Confidence (ABC) Scale classifies fall risk. Postural sway parameters (RMS and centroidal frequency) were captured with accelerometers. A 2 × 2 mixed MANOVA compared groups and conditions. Results: A significant main effect of incline was observed (F(6,25) = 2.980, p = .025, partial η² = .417). Sway RMS and sagittal RMS were greater on level ground than on the incline (p < .001). No significant group differences or interactions were found. Conclusion: Inclined walking reduced sway amplitude while slightly increasing sway frequency, suggesting adaptive neuromuscular control. Incline walking may create a rigid or frizzing postural strategy in PLHIV regardless of fall-risk status. These findings highlight the importance of incorporating environmental challenges into fall-risk assessments and interventions.