Peripheral catheterization is a common medical product, used by doctors or nurses. Right knowledge and approach could prevent complications such as thrombophlebitis. The aim of this study was to investigate nurses´ knowledge and guideline adherence in reference to peripheral catheterization. Method: a quantitative structure was used and 26 nurses participated in the survey. The results showed that the nurses had good knowledge on prevention of complication when using peripheral catheterization, the choice of placement and documentation on the dressing. However, the nurses showed inadequate knowledge regarding the basic hand hygiene, injection port, blood sampling and inspection of the peripheral catheterization. The result indicate that one third of the informants have insufficient knowledge and thereby inadequate guidelines adherence.