The present invention provides a method for the preparation of a cross-linked hydrophilic coating of a hydrophilic polymer on a substrate polymer surface of a medical device, involving the use of a polymer solution comprising 1-20% by weight of a hydrophilic polymer, 0-5% by weight of additive(s), and the balance of a vehicle with plasticizing effect on the hydrophilic polymer, wherein the vehicle comprises at least one plasticizer having a solubility in water of at least 6 g/L, a boiling point above 210°C at 760 mmHg, and a Hansen ´ H parameter of less than 20. Furthermore, the invention provides a medical device, e.g. a catheter or guide wire, provided with such a hydrophilic coating. The invention also provides the use of a specific polymer solution for the preparation of a cross-linked hydrophilic coating.