The toll includes federal troops, rebel fighters, and civilians who died or went missing during both the first conflict -- from 1994 to 1996 -- and the second, which began in 1999 and continues today.
Djabrailov also said ethnic Chechens make up no more than one-quarter of that death toll, although he failed to provide any explanation for this.
He told RFE/RL's Russian Service that his estimates were virtually impossible to confirm.
"This figure is for the total losses in the Chechen republic, of federal forces as well as of people who went missing," Djabrailov said. "We quote this figure, although, officially, it is almost impossible to back up with facts."
The Russian government has yet to issue official death tolls for either conflict, although officials occasionally mention various figures. But these are, as a rule, dismissed by human rights groups as gross underestimates.
According to official figures, some 10,000 federal troops have been killed in both wars so far. Independent experts and rights advocates put this figure at up to 40,000.
As for civilians, the human rights organization Memorial says up to 75,000 Russian and Chechen civilians have lost their lives since 1994.
The high death toll given by Djabrailov therefore comes as a surprise for many Russians, particularly since the Chechen government remains largely loyal to the Kremlin, and would likely not be likely to highlight the grimmest aspects of the war.
But this does not mean human rights campaigners have welcomed his declaration.
Alexandr Cherkasov, a Chechnya expert at Russia's Memorial rights organization, slams Djabrailov's statement as politically motivated. He says the Chechen government, just like the federal authorities, has never attempted to keep a record of all the dead and the missing.
"The majority of figures quoted by today's politicians have a solely political purpose," Cherkasov said. "It is contemporary post-modernism: 'How many? As many as is required.' Neither during the first nor the second war did governmental structures calculate the death toll. The reasons are clear: the death of civilians would have contradicted the idea that order was being brought to Chechnya."
Alexei Malashenko, a prominent expert on Chechnya, describes Djabrailov's figures as exaggerated. Like Cherkasov, he sees Djabrailov's declaration as purely political.
But why would Djabrailov, a top official in Chechnya's pro- Russian government, seek to inflate the death toll?
For Malashenko, Djabrailov's comment is simply an expression of resentment toward the Kremlin.
He told RFE/RL that many Chechens, even those within the government, still blame Russian forces for causing so much devastation in Chechnya.
"One can understand that people who were involved in this conflict would try to show its horror," he said. "This is absolutely normal for Chechnya, which truly suffered tremendously from this conflict. This is a form of criticism of the central [federal] power, to say that Moscow has made a huge amount of mistakes and has inflicted irreplaceable losses on the Chechen community."
Malashenko says ethnic Russian civilians also suffered extremely bad treatment from both federal forces and Chechen rebels during the two wars. Rights groups regularly accuse federal armed forces of brutalizing and slaughtering large numbers of ethnic Russians residing in Chechnya, particularly during the mass exodus that followed the beginning of the first war.
But Malashenko nonetheless cast serious doubt on Djabrailov's claim that ethnic Chechens make up only one-fourth of those who died in Chechnya.
For RFE/RL's full coverage of events in Chechnya, see "Crisis In Chechnya"