PurposeThis study aims to test the relationship between two measures of sociocultural adjustment (perceived acceptance and work standard) with work attitudes and behavior and with psychological distress following an internal merger of two previously distinct working groups within the one business.Design/methodology/approachA field study, using a cross‐sectional design, was used to assess the reactions of 250 employees (host employees=170; relocated employees=80) who had undergone an internal merger within a communications company.FindingsPerceived acceptance and work standards following the merger were significantly related to work attitudes and behavior for both the host and the relocated employees. There was no direct relationship between perceived acceptance and work standards with psychological distress. However, work attitudes and behavior were found to mediate the indirect effect of perceived acceptance and work standards on psychological distress.Research limitations/implicationsThe findings must be considered within the limitations of the study which include the use of a cross‐sectional design and testing within one business setting.Practical implicationsThe research suggests that ensuring that employees from both pre‐merger groups are assisted in feeling accepted in the new culture and that both groups are giving support and resources to maintain work standards are important factors in managing post‐merger integration.Originality/valueThe study is the first to empirically test Berry's concepts of sociocultural adjustment, neutrality and asymmetry within an internal business merger.