Purpose: This purpose of study was to describe the adaptation process in the workplace in Korean adults with alcohol use disorder. Methods: Twelve participants were recruited at hospital outpatients, Alcoholic Anonymous, and addiction treatment centers from October 2016 to January 2017. Inclusion criteria were Korean adults aged 18 and older who were diagnosed with alcohol use disorder and had a job for at least one year. Data were analyzed using Strauss and Corbin’s grounded theory method. Results: From open coding, 74 final concepts, 18 sub-categories, and 10 categories were identified. Results showed that the central phenomenon was ‘struggling to stand confidently’. The core categories were ‘withstanding life by embracing reality as an addict’, and the adaptation process appeared ‘selection stage’, ‘determination stage’, and ‘management stage’. The adaptation process of Korean adults with alcohol use disorder in the workplace was compared to ‘pearl in oyster’, which can be a process of breaking through pain. Conclusion: Our study findings provide an in-depth understanding of the experiences of an alcoholic’s job life. Mental health nurses need to be actively involved in developing vocational rehabilitation programs for addicts.