The policy announcement comes just over a week after Prime Minister Manmohan Singh pledged to crack down on defence corruption following a string of graft scandals that has put his government on the back foot.
The defence ministry said the new policy would seek the "highest standard of transparency" in arms purchases for the country's million-plus military, the world's fourth largest.
"(It) aims to balance the competing requirements of expediting capital procurement... and conforming to the highest standards of transparency, probity and public accountability," the defence ministry said in a statement.
In a bid to boost India's domestic defence industry, the policy gives first right of refusal to Indian vendors, according a "higher preference explicitly to the Buy Indian, Buy and Make Indian" approach.
Defence Minister AK Antony in a foreward to the policy paper said he hoped the procedure will be a "progressive step aimed at giving impetus to indigenisation, creating (a) level playing field... and expediting the procurement process as a whole".
India is negotiating a series of huge procurement contracts, including for fighter jets, combat helicopters, as well as artillery, drones and electronic warfare systems, as it seeks to update its ageing military hardware.
Dr Singh, a week ago, warned he was committed to make purchases of military hardware more "transparent, smooth, efficient and less vulnerable to unethical practices".
In February, public anger over alleged bribes paid by Italian company Finmeccanica to secure a $748 million (Rs 3,600 crore) contract for 12 helicopters forced New Delhi to order an investigation and suspend the deal.
Italian prosecutors suspect kickbacks worth around 50 million euros ($64 million or Rs 362 crore) were paid to Indian officials to ensure Finmeccanica's British unit AgustaWestland won the contract, according to Italian media reports.
A preliminary inquiry report by the government has linked four firms, four Westerners and seven Indians to the bribery allegations.
The governing Congress party, up for re-election in May next year, has been hit by a string of scandals. Two ministers resigned last month after one was accused of interfering in a graft probe and another was linked to a bribery allegation.
The defence scandal erupted at a time when the government was already fighting charges by the national auditor that under-pricing of the sale of telecom spectrum and cut-rate allocation of coalfields cost the exchequer billions of dollars.
The controversy paralysed Parliament and derailed measures to further open up the state-controlled economy as growth plunged to a decade-low of five percent in the last financial year.