Abstract A new method has been developed to prevent proppant flowback from a propped hydraulic fracture. The method consists of mixing the proppant with fiber elements before pumping the proppant into the fracture. The results of an experimental program, in which the goal was to better understand the mechanics of the reinforcing fiber on the proppant pack, are presented. The effects of fiber and sand properties on sandpack strength have been studied for an optimal use of the fiber. A macroscopic model has also been developed based on fiber and proppant properties. Laboratory tests on proppant with a low fiber content indicate a favorable agreement between the model prediction and the flowback tests.