Abdullah, flanked by lance-bearing liveried cavalry, was escorted by President Abdul Kalam on Thursday to New Delhi's Central Vista parade grounds.
Manmohan Singh, the Indian Prime Minister, his cabinet colleagues and Saudi delegates also attended the parade which wound past a World War II memorial raised in honour of India, a major contributor to the Allied forces.
The celebrations mark India's transition to a republic in 1950 after independence in 1947.
But several blasts triggered by Maoist rebels in eastern India provided a jarring note to the celebrations held amid tight nationwide security.
The military displayed its Russian-built T-90 tanks as well as howitzers and models of its nuclear-capable Agni (Fire) ballistic missile which has been tested more than five times since 1993.
India, which budgeted $14 billion for defence in the fiscal year ending 31 March 2006 and has emerged as Asia's largest market for Western military hardware, also showed off a model of a French-designed Scorpene submarine due to join its naval fleet by 2011.
Thousands of troops from various services including elite commando units with machine guns guarded the fortified venue to prevent attacks by Kashmir's separatist fighters who had vowed to disrupt the annual celebrations.
The military displayed its latest
The Indian air force, the world's fourth largest, staged flypasts of its frontline Sukhoi-30 interceptor jets and Mirage-2000 multi-role fighter planes.
Train services meanwhile were thrown out of gear in eastern Bihar and Jharkhand states as some 60 left-wing guerrillas dynamited train tracks in the insurgency-hit area, a spokesman from the state-run utility said.
The rebels also bombed a police station in Bihar's Banka district, local police chief D N Gupta said. The rebels attacked officers and stole arms and ammunition, he added. One policeman was wounded in the attack.
Maoist rebels also engaged police with gun battles in Jharkhand state as they tried to enforce a general strike.
Indian troops, meanwhile, foiled a major attack in the disputed Himalayan state of Kashmir after soldiers recovered military-grade explosives including anti-tank landmines close to the site of a Republic Day parade, officials said.
The ambush was set near a school parade ground in the district of Poonch in southern Kashmir, the officials said, adding that troops also recovered grenades and other weapons in overnight swoops across the troubled region.
Maoist rebels and Kashmiri fighters had called a boycott of the Republic Day celebrations.