A portable infusion pump is essential to sustain the 46-hour continuous administration of 5-fluorouracil in the folinic acid, fluorouracil, and oxaliplatin (FOLFOX) and folinic acid, fluorouracil, and irinotecan (FOLFIRI) protocols in colorectal cancer chemotherapy. However,the accuracy of the 5-fluorouracil dose administered via the infusion pump and patient compliance varies because the infusion rate changes depending on the viscosity of the drug, temperature, etc. In addition, the termination of administration based on the patient's judgment may influence these factors. In the present study, the amount of 5-fluorouracil remaining in the infusion pump and the administration time were investigated. As a result, the median amount that was found to remain in the pump was 49 mg, which was 2.0% of the average dosage, and an median administration time delay of 70 min was obtained. A questionnaire survey revealed that a majority of the patients felt insecurity about in adequate administration and administration time delays. These results indicate that customizing capacity modulation in the infusion pump corresponding to the patient's usage or seasonal variability of air temperature, and patient education may be important to improve patient compliance.