As an excretory organ in the urinary system, the kidney greatly influences an individual’s well being by preserving homeostasis through different mechanisms, such as regulating electrolytes, pH, and blood pressure. Human kidney fibroblasts are responsible for the synthesis of collagen I of the extracellular matrix. Also, kidney fibroblasts synthesize erythropoietin, an important glycoprotein hormone that controls the production of red blood cells. They produce prostaglandins, a class of autocrine or paracrine hormones, which help maintain water and electrolyte homeostasis. Renal fibrosis, a disorder that may escalate to chronic kidney disease, is often related with excessive deposition of extracellular matrix. HKF in culture provide a useful in vitro model for studying the relationship between fibroblasts and renal disease. They are also useful tools to stablish in vitro disease models for High Throughput and High Content Screening.