Nganga age 75 joined the Board of Safaricom Ltd on 6 May, 2004 and was elected Chairman on 16 January, 2007. He is a holder of a BA degree from Makerere University and served as Permanent Secretary in the Ministries of Finance, Foreign Affairs and Health. Nganga has been extensively involved in the tea industry and was Chairman of the Tea Board of Kenya. He is a past Chairman of the National Bank of Kenya. Currently, he holds Chairman Position for G4S Security, Car & General Kenya and is a member of the Board of Kakuzi Limited.