Anaphylaxis and urticaria are common presenting allergic complaints. Affecting up to 2% of the population, anaphylaxis is a serious, life-threatening allergic reaction. Although not life-threatening, urticaria is a rash of transient, erythematous, pruritic wheals that can be bothersome and affects up to 25% of the population. All cases of anaphylaxis warrant thorough clinical evaluation by the allergist–immunologist, although most cases of urticaria are self-limited and do not require specialist referral. This article offers an overview of our current knowledge on the epidemiology, pathogenesis, triggers, diagnosis, and treatment of anaphylaxis and urticaria.