OBJECTIVES: Before 2006 bed occupancy rates during winter periods were above the good management threshold (85%) in Jessa Hospital paediatric ward (Hasselt, Belgium), with peaks above 100%. This causes pressure on bed and people management expressed in bad QoC scores. We evaluated two methods to improve the scores and their investment costs. METHODS: Option A is extending the number of paediatric beds until the unit operates under the 85% threshold during the whole winter season. Option B is introducing rotavirus vaccination to infants with high coverage in the catchment area. A hospital with 36 paediatric beds was selected as pilot design. Bed occupancy rates/day over a period of 6 years (2004-2009) were collected, including pre- and post-introduction of the vaccine in 2006. Estimated birth cohort was 7,000/year in the catchment area. For Option A total cost per year was calculated referencing to the observed pre-vaccination period. For Option B cost of vaccinating the birth cohort with implications on hospital savings was calculated applying the observed post-vaccination period. Total cost per year for each option was compared. RESULTS: Option A: extending hospital ward with 4 extra beds to remain under the threshold, costs about €436,000/year and the threshold may still sometimes be exceeded. Option B: vaccination program in the area costs €420,000/year, leading to a 41% reduction in the number of bed-days for gastro-enteritis during the winter, equivalent to €82,000/year of cost offsets. Total cost of Option B is therefore €338,000/year with an overall 82% bed occupancy rate/day, being below the threshold throughout winters.  CONCLUSIONS: Option B with vaccination is cheaper than option A with extra beds. Moreover it maintains the occupancy rate below the safety threshold during the whole winter period, and thus guarantees better QoC scores in the paediatric ward.