ObjectiveThe primary objective of this review was to analyse the differences in efficacy between the administration of intermittent and continuous/expanded perfusion of piperacillin-tazobactam. Secondary objectives were to analyse the differences in safety, pharmacokinetic/pharmacodynamic parameters, and cost-effectiveness between the two forms of administration. MethodWe performed two different independent bibliographic searches. We encountered a total of 38 articles, and the final number included in the study was 6. We analysed the articles and collected the following variables: design, treatment administered to each group, total number of patients and number of patients in each study, variables collected in each study, and results. ResultsWe encountered significant differences in the primary variable in two of the six studies favouring continuous/expanded perfusion. The study by Lodise et al found differences (P=.04) in mortality (31.6% for intermittent perfusion vs 12.2% for continuous/expanded perfusion). The study by Lorente et al found differences (P=.001) in terms of clinical recovery (56.5% for intermittent perfusion vs 89.2% for continuous/expanded perfusion). As for secondary variables, we only found differences in one of the studies in relation to cost-effectiveness, in favour of the group who underwent continuous/expanded perfusion method. ConclusionThe analysed data suggest that continuous/expanded perfusion would be at least as effective as intermittent perfusion, and that it could be more effective in severe patients with infections from more resistant micro-organisms such as Pseudomonas aeruginosa. Additionally, this form of administration is more cost-effective, at least in theory.