In 1980 he created his own brand, STEFANO CHIASSAI, a total look line, distributed worldwide.

In 1985, together with his wife Alessandra, he founded the style consultancy office, SCS Studio Chiassai.

In 1987 he showed his brand STEFANO CHIASSAI on the runway, which saw him center-stage at Pitti Trend, Pitti Uomo, and during the Milan fashion weeks, where he earned recognition from industry peers and the specialized press.

Since 1994, after retiring the brand, the Studio's work has focused on style consultancies and researching trends for numerous brands. Stefano's research is grounded in the luxury sector with a strong urban imprint. Since the early 2000s he designs collections of menswear for international brands. Through his aesthetic, he seeks to reconcile the world of traditional workmanship with that of new technologies.