Vancomycin is a glycopeptide antibiotic that needs to be dosed to achieve target trough levels of 15-20 mg/l. Dosing can be challenging in ICU patients. To optimise therapy, in ICU-pharmacy collaboration, a dosing protocol was introduced on the ICU of the Medical Center Leeuwarden, the Netherlands. The effectiveness in obtaining timely adequate trough levels was evaluated. We retrospectively analysed data from 59 patients. Results show that pharmacy involvement and introduction of the dosing protocol resulted in early adequate trough levels (p = 0.016). Introduction of the protocol alone resulted in non-significant early accurate trough levels. The protocol should be used with caution in patients with a possibly unreliable estimated glomerular filtration rate. Careful protocol introduction is important.