Acceptance and commitment therapy (ACT) is a developing approach for chronic pain. The current study was designed to pilot test a brief, widely inclusive, local access format of ACT in a UK primary care setting. Seventy-three participants (68.5% women) were randomized to either ACT or treatment as usual (TAU). Many of the participants were aged 65 years or older (27.6%), were diagnosed with fibromyalgia (30.2%) and depression (40.3%), and had longstanding pain (median = 10 years). Standard clinical outcome measures included disability, depression, physical functioning, emotional functioning, and rated improvement. Process measures included pain-related and general psychological acceptance. The recruitment target was met within 6 months, and 72.9% of those allocated to ACT completed treatment. Immediately post treatment, relative to TAU, participants in ACT demonstrated lower depression and higher ratings of overall improvement. At a 3-month follow-up, again relative to TAU, those in ACT demonstrated lower disability, less depression, and significantly higher pain acceptance; d = .58, .59, and .64, respectively. Analyses based on intention-to-treat and on treatment "completers," perhaps predictably, revealed more sobering and more encouraging results, respectively. A larger trial of ACT delivered in primary care, in the format employed here, appears feasible with some recommended adjustments in the methods used here (Trial registration: ISRCTN49827391). Perspective: This article presents a pilot randomized controlled trial of ACT for chronic pain in a primary care setting in the United Kingdom. Both positive clinical outcomes and ways to improve future trials are reported.