Cell culture of glomerular mesangial cells (MC) has been available to most renal research laboratories since the early 80s. Key to a large number of studies on the biochemistry and molecular biology of the glomerulus, MC in culture have extensive analogies with this in vivo rather undifferentiated intercapillary cell population. They proliferate in response to mitogens and growth factors, can be growth-arrested by withdrawal of serum or 3D culture in collagen gels, synthesize an extracellular matrix that includes interstitial collagens, and display most markers of mesangial origin, including a functional contractile apparatus. As proliferation and matrix synthesis/degradation in vitro are regulated by cytokines and growth factors, cultured cells are an ideal tool for studying pathophysiological events such as mesangial expansion, scarring, and glomerulosclerosis. Current techniques for MC isolation and culture are reviewed, with several methodological issues relevant to the characterization, propagation and long-term maintenance of functional clones.