He was appointed Provincial Commissioner for Central Province by President Daniel Arap Moi in 1979, a post which he retained until 1985, after which he was appointed Director of Tourism in the Ministry of Wildlife and Tourism.
In 1997 he was elected as a KANU MP and retained his seat after moving to the LDP wing of NARC in 2002.
In April 2008 he was appointed as assistant minister of Defence by President Mwai Kibaki where he served until 2013.
The former senator also served as chairman of Wiper Democratic Movement Kenya until his resignation.
David Musila is the author of a book titled "Seasons of Hope" that is a written memoir of his life as a public servant.