This work provides a comparison between the most commonly used classification equipment in the treatment of minerals - hydrocyclones and spiral classifiers - considering their applications and costs. Although in use for decades in the mining industry, spiral classifiers have lost a lot of their importance due to the development of cyclones. This trend, however, is now being reversed, and in the last few years there has been an increasing interest in spiral classifiers, in view of their advantages over cyclones, such as: possibility of obtaining more thickened solids; less by-pass; great durability; lower operating cost. This work approaches the different aspects related to the installation, operation and costs of maintenance of these machines, giving a critical comparison of the involved costs.