Najib said he hoped the task force led by his deputy would be able to curb the spiraling number of cases, according to local media reports.
Eighty-two people have died from the flu-like illness from January until June 21, more than triple the number in the same period last year. The number of cases has soared 3.5 times to more than 42,000, suggest health ministry figures.
The deadliest year on record in Malaysia was 2010 when 134 people died from dengue. More than 43,000 cases were reported for all of last year, with 92 deaths, up from 35 dead in 2012.
"We hope the establishment of this special task force will be able to curb the rise in dengue cases and at the same time implement preventive measures more effectively throughout the country," Najib was quoted by the Star as saying.
Authorities have repeatedly urged people to make sure their surroundings are free of mosquito-breeding places, such as stagnant water collecting in empty flower pots, dumpsters and construction sites.
They have also appealed to those with symptoms, such as nausea, headache and severe muscle and joint pain, to seek hospital treatment.
In severe cases, the illness nicknamed "break-bone fever" can cause internal bleeding, organ impairment, respiratory distress and death.
Repeated hot spells this year have contributed to more cases of dengue fever, as it speeds up the life cycle of the Aedes mosquito that carries the virus and enhances replication of the pathogen, experts say.
The World Health Organisation calls dengue one of the fastest-growing viral threats globally, especially in the tropics.
Dengue is transmitted by the Aedes aegypti mosquito, which can pick up the virus from an infected human and transmit it to the next person it bites.
According to the World Health Organisation, the disease may be infecting up to 50-100 million people each year.
There is no vaccine so prevention focuses on mosquito control.