The shares were priced at $26 (pounds 16) yesterday but are expected to open $5 higher when they go on sale, netting the company over $800m. The move is also expected to spur other designers to take their fashion houses to Wall Street.
"This is the biggest payday in the history of Seventh Avenue," said Alan Millstein, editor and publisher of the Fashion Report, referring to the traditional American home of the fashion industry.
Polo's strong brand name, established menswear line, growing line in womenswear and opportunities for growth are all drawing Wall Street's eye.
"In fashion, things are quixotic," said Mr Millstein. "But Ralph Lauren is not a designer - he's a businessman first. He doesn't sit around with a sketch pad. That makes him a better bet for the investment community."