Ilídio Inácio began his activity linked to radio in Santarem, doing announcements in a popular fair and, on Sundays, at the República Garden, where a sound booth had been installed by Captain Jaime Varela Santos. In that Garden, passers-by could "ask for records to be played", dedicated to family members, friends and for romances that were still secret. Ilídio Inácio worked in Radio Ribatejo as an announcer during the first three years of its existence, a job he shared with Oliveira Mendes. In 1953, he received an invitation from Rádio Clube do Norte, in Porto, which belonged to Adolfo Quaresma, a former military officer who died shortly afterwards. Already a reporter, announcer and producer, the Quaresma family opened the doors for him in terms of entering the station's ownership. According to him, an announcer had to be "an outstanding professional, very cultured and well-informed about world problems, as well as knowing pop music and sport. In his opinion, there should be a radio school to train production assistants, technicians and announcers. The reality of Porto was different from Lisbon, as the city was already served by SNI courses and Radio University.
In terms of uniting radio and journalism, he advocated the direct line between the Jornal de Notícias newspaper and the radio booth, even alluding to a project to move the radio studios to the upper floor of the newspaper building. "I would also like to see short newscasts that would keep the listener updated throughout the day.” Besides Jornal de Notícias, Ilídio Inácio had a close relationship with Norte Desportivo, which was produced on the premises of another of the city’s important newspapers, O Primeiro de Janeiro, on rua de Santa Catarina street. In Porto, he would be well known as a producer of radio drama, with Eça de Deus as author, and of football and roller hockey talk shows and interviews, reporting on F.C. Porto domestically and in international matches. He was an enthusiast and precursor of the work of reporters near the pitch with a range of information about the game and interviews with the players. José Barroso was, for years, Ilídio Inácio's official reporter. On the producer's sports afternoons and evenings, they would be joined by Desidério Amaro, with original phrases and a Brazilian accent and Brazilian terms, because he was an emigrant in that South American country, and Fernando Maciel, pitch-side reporter and remembered for his work in the game in which the player Pavão died on the pitch.
Ilídio Inácio recommended the uniting of Emissores do Norte Reunidos, then divided amongst various stations, which would allow for an improvement in the quality of the programmes. In fact, Emissora Nacional would buy those stations, which would lose their traditional names, and Ilídio Inácio developed his activity as an independent producer through the company Quadrante Norte. Before that, he had worked with Sonarte. As an entrepreneur, Ilídio Inácio owned a private studio where he worked with the technician Alberto Mendonça and two announcers, at Rua Júlio Dinis, 803, 1st left, then one of the new avenues of Porto, with renowned shops and cafés and an area for company offices. It was later extended with the inauguration of an emblematic shopping centre in the city and in the country, Brasília. After the nationalisation of radio in December 1975, he provided services as an independent producer, with a studio in Senhora da Hora (rua Ator Vasco Santana, 52), for Rádio Comercial Norte, an extension of the former Rádio Clube Português in Porto, and for Rádio Renascença. These services included sports reports. The Resenha Desportiva programme became the longest running on Portuguese radio with Aníbal Barroso as the writer and person responsible for this Ilídio Inácio production. His sound and image company was wound up in 2011.