The world's fourth-largest communications group cited improvements in Asia-Pacific and the Americas for growth in revenue to £604 million.
But Publicis said this contrasted significantly with the "relatively slack overall activity in Europe, where differences from one country to the other persisted".
Publicis, whose empire includes the Saatchi & Saatchi, Leo Burnett and ZenithOptimedia networks, managed organic growth of only 1.8 per cent in Europe.
Meanwhile, other regions performed much better, including North America and Asia-Pacific, which reported figures of 4.8 per cent and 7 per cent respectively.
Nevertheless, agencies within Publicis Groupe landed more than £790 million- worth of new business during the period.
Maurice Levy, the Publicis chairman, said: "The numbers achieved in the first quarter make me confident."