Dry-docking is an integral part of a vessel's life. With a frequency of approximately 30 months, flag legislation and classification society rules bring the vessel to a shipyard's dry-dock for an intermediate or special survey. Dry-docking cost is a significant element of the ship's operating cost and is always presented as a six or seven figure amount. This paper, for the first time in the literature, unveils the determinants of dry-docking cost and hence equips the decision maker with a valuable tool for the cost side of his ventures. We have collected 414 cases of ship repairs from one of the biggest ship repair yards of the Persian Gulf, over a time span of 4 years. Making use of this primary database, we develop a simultaneous equations model and express dry-docking cost as a function of ship type, size, and age. Other important determinants are also incorporated into the model such as upswings or downswings in the shipping cycles and the shipping company's capacity as an effective negotiator. The method of estimation is Generalized Method of Moments and our results shade light on an issue, which has never before been effectively dealt with, given its immense practical significance for the decision maker.