Fibrosis results from the excessive production of extracellular matrix proteins by myofibroblasts. It has recently been reported that in the heart, myofibroblasts develop chondrocyte-like properties following myocardial infarction as fibrosis progresses and tissues stiffen. However, the nature of these chondrocyte-like myofibroblasts remains unclear. In this study, we found that the expression of the proline- and arginine-rich end leucine-rich repeat protein (PRELP) was upregulated in hearts and livers stiffened by fibrosis with chronic inflammation. Moreover, we established that Prelp was specifically expressed in chondrocyte-like myofibroblasts. Prelp expression was found to be regulated by the transcription factor SOX9, and in cardiac and liver myofibroblasts, Prelp-knockdown was observed to reduce collagen expression. These findings reveal that PRELP is specifically expressed in chondrocyte-like myofibroblasts and that it promotes collagen production. PRELP could thus serve as a novel therapeutic target for treating fibrosis.