This study was designed to focus on the patient perspective in a reorganisation of care processes at a cancer day care unit (CDU). The effects of dose banding and of taking blood samples one day (or more) before the day care treatment (on Day −1) are investigated in terms of throughput efficiency and perceived service quality. Data were collected by mapping patient processes in detail and surveying patients in two CDUs at a university hospital (n = 308). A univariate model was used to investigate the effect of these factors on patient throughput time, and perceived service quality was examined with multiple linear regression. Taking blood samples on Day −1 decreases patient throughput time and increases the perceived service quality by improving the patient's perception of technical expertise and the outcome. This has a globally positive effect on patients' perceived service quality. Dose banding affected neither patient throughput time nor perceived service quality. Taking the pretreatment blood sample on Day −1 can be considered an important process design characteristic, as it increases both efficiency and service quality.