PurposeTo examine organizational diagnostics taken from the best practice model of change as organizational diagnostic factors in a specific type of business such as family businesses. These account for many of companies in Asia and are regarded as a special from the mixture of management focus on business, family and ownership.Design/methodology/approachIn order to manage changes in family business successfully, the organizational diagnostic factors are analyzed from executives' in‐depth interviews with Thai family businesses that implement new IT systems.FindingsCommunication, generation, ownership, family structure, politics and national culture are six diagnostic factors in Thai family businesses that are not the same as the model of change.Originality/valueConsultants and change agents in family businesses, especially in Asia, can use these factors as an additional guideline for their effective change management.