The mobile phone operator had 15.2 million customers at the end of June, compared with 11 million a year ago, but the rate of growth has fallen below 40 per cent for the first time since September 2006.
Vodafone Egypt and the other two Egyptian mobile operators, Mobinil and Etisalat Misr, have all benefited from an increase in the size of the mobile phone market over the past year.
More than 11 million Egyptians bought mobile phones during 2007, many of them for the first time.
Mobinil, which is controlled by Orascom Telecom, has yet to disclose its customer numbers for the quarter to the end of June. It had 16.2 million mobile phone users at the end of March.
Etisalat had 3.1 million customers at the end of December.