A range of clinical syndromes may present with psychiatric symptoms, both in and out of hospital settings. In such situations agitation, suicidality, communication difficulties and legal aspects often play a role, making diagnosis and treatment a challenge. Based on several case studies, we illustrate how the recently-published Dutch open access source 'Acute Psychiatry' (www.acutepsychiatrie.com) can be of help in acute psychiatric presentations both within and outside psychiatric hospitals.