Reliance on alcohol, the use of illegal drugs and the misuse of prescription medication can all be highly problematic in the workplace. Simply dismissing people who exhibit such problems can mean the loss of valued employees who are going through a bad patch in their lives – a move that can prove quite costly in the long run – with the additional cost that others may perceive the organisation as uncaring and unsupportive of its staff. Such a perception may then lead to problems of recruitment and retention. But, if the problems of alcohol and drugs misuse in the workplace are not tackled, the cost to the organisation and its employees can be even greater. A good understanding of the issues involved is therefore an important thing to develop.