He does so whenever he considers he has delivered a good one-liner. Asked to comment on the fact that Vilnius appears to be thriving under the former communist government that forced him from power, he quotes Tolstoy: "Despite the best efforts of physicians, the ill man became healthy."
He also laughs as a self- defence mechanism. Looking at the current debate on Nato enlargement, he titters as he mimics Moscow's protestation that the admittance of little Lithuania to the alliance would represent a "danger" to Russia.
He titters again as he thinks of Western attempts to win Russia over to the idea of expansion. "Discussion with Moscow. Seriously! This is political comedy of the highest order. Far away countries like Portugal or Venezuela must look on with amazement. But for countries such as ours, this political comedy is a very black comedy indeed."
Like nearly all Baltic politicians, Mr Landsbergis believes that the long-term security of Lithuania, Latvia and Estonia can only be achieved through full Nato membership.
He was relieved to hear Nato Secretary General Javier Solana repeat that such a scenario remained possible - though by no means inevitable - during his brief visit to Lithuania this month.
But he has become alarmed at the growing number of Western politicians who, in addition to ruling out Baltic participation in a likely first wave of Nato expansion, have begun suggesting the need to consider alternative long-term security models.
Douglas Hurd, the former British foreign secretary, crystallised such thinking late last month by openly questioning whether Britain or the United States would ever be prepared to defend the Baltics with nuclear weapons and proposing that, rather than Nato, the countries look to join a Scandinavian security pact led by Finland and Sweden.
Other proposals for enhanced Baltic security - short of Nato membership - include a big step of military links and exercises under Nato's Partnership for Peace programme and an intensification of the drive to admit the countries to the European Union.
Mr Landsbergis is not impressed. Nor, on this occasion, is he amused. "Partial security for us can also be seen as partial insecurity," he points out. "If we are left outside Nato we might find ourselves being used as a coin in barter, an object that can be sold for seemingly more important things such as a 'new world order'.
"If we lower the line and say we are no longer trying to achieve full military security, what next?" he asks. "In future there might be objections to our bid to join the European Union. If we are left with only partial security, the gate will be open to pressure, intervention, destabilisation."
Having spearheaded his country's drive for independence five years ago, Mr Landsbergis was unceremoniously ousted from office in 1992 when disillusioned Lithuanian voters became the first in the region to return former communists to power.
But the 63-year-old former musician is hoping for a comeback this autumn in elections which look certain to see a sharp rise in support for his Conservatives of Lithuania and other centre-right forces.
If he were to wield power again, Mr Landsbergis says he will certainly take a tougher line with Moscow than the current government. But he would not seek outright confrontation.
"I am not that crazy," he says. "I will defend Lithuanian interests to the last. But in the end, we have to live with Russia and can only hope that true democracy takes hold there. In the meantime, all we want is to belong to the secure world of the West. We do have the right to belong to it. Or don't we have a choice?"