Mr Saldanha (64), who also held the portfolios of Science and Environment, was brought to a private hospital at around 1.30 am after he suffered a massive cardiac arrest. The doctors treating him said that they tried to revive him for almost two hours before declaring him dead.
The body has been shifted to Goa Medical College and Hospital. Chief Minister Manohar Parrikar also visited the hospital.
The Bhartiya Janata Party (BJP) legislator representing Cortalim constituency, Mr Saldanha had joined BJP little before the March 3 elections and was one among the five catholic candidates who were given ticket by the party.
He was elected twice to the assembly, first being in 2002 on a United Goans Democratic Party ticket. He was elevated to cabinet rank by then Parrikar-led government.
Mr Saldanha had been in the forefront of the movement seeking right to traditional fishermen. As leader of the National Fishworkers' Forum (NFF), he had also fought against the special economic zones in the state.