He is known for designing the Western Electric Model 500 telephone, the Westclox Big Ben alarm clock, and the Honeywell T87 Round Thermostat.

Sometimes compared to Raymond Loewy and other contemporaries, Dreyfuss was much more than a stylist; he applied common sense and a scientific approach to design problems, making products more pleasing to the eye and hand, safer to use, and more efficient to manufacture and repair.

His work helped popularize the role of the industrial designer while also contributing significant advances to the fields of ergonomics, anthropometrics and human factors.

In 1969, Dreyfuss retired from the firm he founded,[7] but continued serving many of the companies he worked with as board member and consultant.

This visual database of over 20,000 symbols continues to provide a standard for industrial designers around the world,[8] and has notably been incorporated into works by artists such as Jean-Michel Basquiat.