Deiro left his home to avoid an arranged marriage, and defying his father's wishes that he manage the family businesses, he became a professional entertainer and took engagements in France and Germany playing the chromatic accordion. His success as a performer led the Ronco-Vercelli accordion company in Italy to ask him to demonstrate their new piano-accordions at the Alaska–Yukon–Pacific Exposition in 1908. This world's fair was held in Seattle from June to October 1909. After the fair, he stayed on in Seattle working as a musician in saloons. By this time, he had become a virtuoso at playing a piano accordion. In 1910 he was discovered by an agent for the Orpheum Vaudeville Circuit. His opening debut was at the American Theatre in San Francisco (managed by Sid Grauman) on June 15, 1910. He became an immediate sensation, and began traveling the vaudeville circuit routinely back and forth across the United States and Canada (and other countries as well) as a headliner. During his travels, he met and became friends with another famous Italian accordionist: Pietro Frosini.