Background: MOBILE and ENHANCE were similarly designed randomized trials of walking-impaired adults with relapsing-remitting or progressive multiple sclerosis (MS) who received placebo or 10 mg prolonged-release (PR)-fampridine twice daily for 24 weeks. Both studies showed sustained and clinically meaningful improvement in broad measures of walking and balance over 24 weeks of PR-fampridine treatment. Objective: To evaluate the functional benefits and safety of PR-fampridine versus placebo using a post hoc integrated efficacy analysis of MOBILE and ENHANCE data. Methods: Data from the intention-to-treat (ITT) populations of MOBILE and ENHANCE studies were pooled in a post hoc analysis based on the following outcome measures: 12-item MS Walking Scale (MSWS-12), Timed Up and Go (TUG) speed, Berg Balance Scale (BBS), MS Impact Scale physical impact subscale (MSIS-29 PHYS), EQ-5D utility index score, visual analogue scale (VAS), and adverse events. The primary analysis was the proportion of people with MS (PwMS) with a mean improvement in MSWS-12 score (⩾8 points) from baseline over 24 weeks. A subgroup analysis based on baseline characteristics was performed. Findings: In the ITT population (N = 765; PR-fampridine, n = 383; placebo, n = 382), a greater proportion of PR-fampridine–treated PwMS than placebo-treated PwMS achieved a clinically meaningful improvement in the MSWS-12 scale over 24 weeks (44.3% versus 33.0%; p < 0.001). PR-fampridine MSWS-12 responders demonstrated greater improvements from baseline in TUG speed, BBS score, MSIS-29 PHYS score, and EQ-5D utility index and VAS scores versus PR-fampridine MSWS-12 nonresponders and placebo. Subgroup analyses based on baseline characteristics showed consistency in the effects of PR-fampridine. Conclusion: The pooled analysis of MOBILE and ENHANCE confirms previous evidence that treatment with PR-fampridine results in clinically meaningful improvements in walking, mobility and balance, self-reported physical impact of MS, and quality of life and is effective across a broad range of PwMS.