In intensive care settings, there are very few reports of direct cooperation between pharmacists (Ph) and clinical engineers (CE) in Japan. Since extracorporeal circulation devices such as continuous hemodia ltration, which affect pharmacokinetics, are widely used in these elds, cooperation between Ph and CE is important. Therefore, we evaluated the direct cooperation between Ph and CE for sharing information related to extracorporeal circulation devices. In order to evaluate the efficacy of this cooperation, the total numbers of pharmacist prescription interventions involving extracorporeal circulation devices before and after the cooperation, as well as the time required for these interventions, were compared. The total numbers of interventions before and after the cooperation were 303 and 430, respectively. Of these, the number of prescription interventions related to extracorporeal circulation devices increased signi cantly from 30 cases (9.9%) before to 85 cases (19.8%) after the cooperation (P < 0.001). The percentage of interventions within one 24-hour period also increased signi cantly from 66.7 % to 96.5 % (P < 0.001). After the cooperation, there were 44 cases that received intervention by direct sharing of information with the CE; most of these were related to the antimicrobial drug dosage. The results suggest that cooperation between Ph and CE related to extracorporeal circulation devices can contribute to early intervention with and the proper use of antimicrobial drugs.