Background In the USA, inpatient phlebotomy services are under constant operational pressure to optimise workflow, improve timeliness of blood draws, and decrease error in the context of increasing patient volume and complexity of work. To date, the principles of Lean continuous process improvement have been rarely applied to inpatient phlebotomy.

Aims To optimise supply replenishment and cart standardisation, communication and workload management, blood draw process standardisation, and rounding schedules and assignments using Lean principles in inpatient phlebotomy services.

Methods We conducted four Lean process improvement events and implemented a number of interventions in inpatient phlebotomy over a 9-month period. We then assessed their impact using three primary metrics: (1) percentage of phlebotomists drawing their first patient by 05:30 for 05:00 rounds, (2) percentage of phlebotomists completing 08:00 rounds by 09:30, and (3) number of errors per 1000 draws.

Results We saw marked increases in the percentage of phlebotomists drawing their first patient by 05:30, and the percentage of phlebotomists completing rounds by 09:30 postprocess improvement. A decrease in the number of errors per 1000 draws was also observed.

Conclusions This study illustrates how continuous process improvement through Lean can optimise workflow, improve timeliness, and decrease error in inpatient phlebotomy. We believe this manuscript adds to the field of clinical pathology as it can be used as a guide for other laboratories with similar goals of optimising workflow, improving timeliness, and decreasing error, providing examples of interventions and metrics that can be tailored to specific laboratories with particular services and resources.