Background: Alcohol-related harm is currently estimated to cost the National Health Service (NHS) in England £3.5 bn a year. Of the estimated 1.6 million people with some degree of alcohol dependence, some 600,000 are believed to be moderately or severely dependent and may benefit from intensive treatment. Outcomes from medically assisted withdrawal, also referred to as detoxification, are often poor, with poor engagement in relapse prevention interventions and subsequent high relapse rates. Detoxification is costly both financially and to the individual. It has been found that people who experience multiple detoxifications show more emotional and cognitive impairments. These changes may confer upon them the inability to resolve conflict and increased sensitivity to stress thus contributing to increased vulnerability risk of relapse. The study aims to test the feasibility of using a group intervention aiming to prepare participants for long-term abstinence before, rather than after, they have medically assisted detoxification. The current study will establish key parameters that influence trial design such as recruitment, compliance with the intervention, retention, and sensitivity of alternative outcome measures, in preparation for a future randomised controlled trial (RCT). This paper presents the protocol of the feasibility study. Methods: The study corresponds to phase 2 of the Medical Research Council (MRC) complex interventions guidelines which cover the development and feasibility testing of an intervention. The work is in three stages. The development, adaptation and implementation of the Structured Preparation before Alcohol Detoxification (SPADe) intervention (stage 1), a randomised feasibility study with economic evaluation (stage 2) and a qualitative study (stage 3). Fifty participants will be recruited from two community alcohol treatment services in England. Participants will be randomised in two arms: the treatment as usual arm (TAU), which includes planned medically assisted detoxification and aftercare and the intervention arm in which participants will receive structured group preparation before detoxification in addition to TAU. The main outcomes are duration of continuous abstinence with no incidents of lapse or relapse, percentage of days abstinent and time to relapse. Discussion: The socioeconomic harms associated with alcohol have been well-documented, yet existing treatment options have not been able to reduce high relapse rates. This study will build on existing naturalistic studies underpinned by psychological interventions offered early and before detoxification from alcohol, which aim to reverse automatised habitual behaviours and thus may help us to understand how better to support people to remain abstinent and improve post detoxification outcomes. Trial registration: ISRCTN, 14621127; Registered on 22 Feb 2017.