In 1968, with a A$610 investment by him and his then fiancée Pip,: 203  Smith founded Dick Smith Car Radios, a small taxi radio repair business in the Sydney suburb of Neutral Bay, New South Wales, then later expanded into the car radio business at Gore Hill, dubbing himself the "Car-Radio 'Nut'". This business later became electronics retailer Dick Smith Electronics which grew rapidly in the late-1970s, particularly through sales of Citizens Band radios and then personal computers, with annual sales of about A$17 million by 1978.: 176 

Smith took the business into Asia in 1978, opening a store in Ashley Road, Tsim Sha Tsui, Hong Kong's tourist shopping hub, and publishing an international catalogue edition until the store closed in 1980. That year, stores were also opened in Northern California and Los Angeles.

In 1982, he sold the business to Woolworths for A$22 million, Though Smith retained no shares nor role in the company thereafter, the business continued to trade with his name prominently displayed in every aspect of its operations until closure of its then hundreds of stores in Australia and New Zealand by May 2016.