Background: Lee Silverman Voice Treatment (LSVT) BIG is a well-established exercise program in Parkinson’s Disease (PD), but its effectiveness in other neurological disorders is not well studied. This pilot study examined whether LSVT-BIG similarly improves balance and gait in MS patients compared to PD. Methods: A pilot clinical trial was conducted with two participant groups: MS and PD. Assessments were performed before, during, and after the 4-week LSVT BIG intervention, which followed the established PD protocol of one-hour sessions, four consecutive days per week. Balance and gait were evaluated using the mini-Balance Evaluation Systems Test (mini-BESTest), Timed Up and Go (TUG), and Functional Gait Assessment (FGA). Single-leg stance time on firm, foam, and inclined surfaces was also measured. Data analysis was carried out using mixed ANOVA in SPSS v24. Results: Twelve participants completed the study (6 PD, 6 MS). Both groups significantly improved in mini-BESTest, FGA scores, and timed tasks (p < 0.001). Comparable between-group results revealed, with no significant differences between MS and PD groups (p > 0.5). Conclusions: Similar improvements across groups suggest that LSVT-BIG may also benefit patients with MS. Larger randomized trials are needed to confirm its suitability for this population.