Cardoso was born in Beira, the son of white Portuguese immigrants in colonial Mozambique, where his father ran a dairy processing plant.

[1][3] After the withdrawal of the Portuguese colonial administration from Mozambique in 1974 following the handover of power to the FRELIMO liberation movement in the context of the Lusaka Accord, Cardoso was among the minority of white Mozambicans who remained in the country.

In 1997, Cardoso founded the business daily news-sheet Metical, and was elected to the Maputo city council in 1998.

Nyimpine Chissano was charged with "joint moral authorship" of Cardoso's murder and various economic crimes by the Mozambican Public Prosecutor's office in May 2006.

The Mozambique News Agency reported on 11 May 2006 an anonymous claim that an arrest warrant for Chissano had been rescinded following the intervention of the former president and his wife.