The primary cilium is a sensory, solitary, non-motile microtubule-based structure protruding in the quiescent phase of the cell cycle from the surface of the majority of human cells, including mesenchymal stem cells, osteoblasts, osteocytes, chondroblasts, chondrocytes, fibroblasts, fibrocytes. The aim of this paper is to provide a review of the current knowledge on the primary cilia in connective tissue cells.