But firm sees growth in India and Turkey.
Vodafone’s quarterly revenue has declined steeply across key markets in Europe.
The mobile phone giant suffered its biggest losses in Italy and Spain, where revenue dropped 17.6% and 10.6% respectively for the three months ending June 30 compared to the same period last year.
In Germany revenue dropped 5.1% and in the UK by 4.5%.
The company blamed increased competition for its problems in northern Europe but admitted that European markets on the whole remained "challenging", partly down to weak economies.
The firm met with more success in the emerging markets of Turkey and India, where revenue grew 15.5% and 13.8% respectively.
India’s data usage also increased by 29% compared to the last three months of 2012, particularly amongst 3G customers, who numbered 3.7m as of June 30, contributing to active data customers totaling 41.2m.
CEO Vittorio Colao said: "Although regulation, competitive pressures and weak economies, particularly in Southern Europe, continue to restrict revenue growth, we continue to lay strong foundations for the longer term.
"We have made a good start to the year in our areas of strategic focus: growth in emerging markets has accelerated."