Psychiatric assessments on medical wards of a general hospital are complicated by various factors, including the lack of privacy, medical illness-related factors such as cognitive deficits and communication barriers, and the vagueness of the referral question asked. In this article, we try to guide general psychiatrists who do not routinely carry out such assessments through practical steps from receiving the referral to signing off the case. The key differences in the process and content of psychiatric assessments are discussed, as are diagnostic dilemmas. Subtle aspects of communicating the outcome of the assessments to patients and referrers are emphasised with specific guidance on writing consultation notes. We conclude with a discussion of the principles of biopsychosocial management and judging the outcomes of consultations on medical wards.