Objective Malnutrition can adversely affect recovery, growth and development, but no studies were performed to investigate the nationwide prevalence of malnutrition of hospitalized children in the Netherlands. During three days in November 2007 the prevalence of malnutrition of all newly admitted children in 44 hospitals (7 academic and 37 general) was studied.

Methods All children aged ⩾30 days were included. Measurements of weight and length were performed. SD-scores <−2 for weight for height (WFH) and height for age (HFA) were considered to indicate acute and chronic malnutrition respectively.

Results A total of 424 children matched the inclusion criteria (academic 41% and general 59%). Median age was 3.5 years (range 31 days–17.7 years) and median length of stay was 2 days (range 1–44 days). Overall 18.7% of the children had either WFH or HFA<−2 SD (academic 21.5% and general 16.7%). This group had a significantly longer length of stay compared to children in good nutritional status (median 3 vs. 2 days, P = 0.007). The proportion of children with a HFA<−2 SD was significantly higher in academic hospitals (13.5% vs. 5.7%, P = 0.008). Furthermore, in academic hospitals significantly more children had an underlying disease with an increased risk of malnutrition compared to general hospitals (46 vs. 15%, P<0.001).

Conclusions This unique nationwide study shows that 18.7% of children admitted to Dutch hospitals have acute or chronic malnutrition. This high prevalence underlines the need for routine screening and treatment of malnutrition in hospitalized children.