The consensus that i.v. resuscitation fluids should be considered as drugs with specific dose recommendations, contraindications, and side-effects has led to an increased attention for the choice of fluid during perioperative care. In particular, the debate concerning possible adverse effects of unbalanced fluids and hydroxyethyl starches resulted in a re-evaluation of the roles of different fluid types in the perioperative setting. This review provides a concise overview of the current knowledge regarding the efficacy and safety of distinct fluid types for perioperative use. First, basic physiological aspects and possible side-effects are explained. Second, we focus on considerations regarding fluid choice for specific perioperative indications based on an analysis of available randomized controlled trials.