Fibrosis, which is characterized by the excessive production of matrix proteins, occurs in multiple tissues and is associated with increased morbidity and mortality. Despite its significant negative impact on patient outcomes, therapies targeted to treat fibrosis are currently lacking. Screening for inhibitors of the expression of collagen, the primary component of fibrotic lesions, represents an option for the identification of novel lead compounds for therapeutic development with potentially fewer off-target effects compared with the targeting of multifunctional cell signaling pathways. Here we report on the generation of a stable luciferase reporter system using a fibroblast cell line, which can be used for rapidly screening both activators and repressors of human collagen COL1A2 gene transcription in a high throughput setting. This in vitro screening tool was validated using known agonists (scleraxis, TGF-β, angiotensin II, CTGF) and antagonists (TNF-α, pirfenidone) of COL1A2 gene expression. The COL1A2-luc NIH-3T3 fibroblast system provides a useful and effective screen for potential lead compounds with pro- or anti-fibrotic properties.