Veteran President Nursultan Nazarbayev, who wields sweeping powers while paying close attention to public opinion, ordered the switch the previous day.
The only Soviet-era leader still in power, the 77-year-old has run the Central Asian country since 1989. He is fluent in both languages and switches between them in his speeches.
But many Kazakhs, including some senior officials, are not, and prefer Russian, and cabinet meetings have generally been bilingual too.
But in Tuesday’s meeting, broadcast live on state television, only one participant in the chamber, Education Minister Erlan Sagadiev, was permitted to speak Russian. Exceptions were also made for provincial officials who joined via video.
After independence, many former Soviet republics rushed through the process of severing links with Moscow.
Kazakhstan, which became self-governing in 1991, took things more slowly, in part because ethnic Kazakhs at that time made up less than half of its population.
Four years later, Nazarbayev made Russian the country’s second official language.
In a census compiled in 2009, only 62%of the population said they were fluent in spoken and written Kazakh, compared with 85% in Russian.
The ethnic balance has since shifted, with Kazakhs now making up 69% of the oil-rich nation’s population of 18 million, while ethnic Russians account for just a fifth.
The Russian language has continued to dominate, however, generating public pressure for the government to promote Kazakh more actively.
Kazakh has very little in common with Russian except for some borrowed words.
Nazarbayev last year announced a switch to a new, Latin-based Kazakh alphabet that will gradually replace the current Cyrillic script adapted from Russian.
This month he amended his own decree after many Kazakhs criticized the use of apostrophes combined with Latin letters to denote some Kazakh letters. The new script uses French-style accents instead.
Nazarbayev maintains warm ties with the Kremlin and was credited with helping to mend fences between Moscow and Ankara in 2016 after they fell out over Turkey’s downing of a Russian warplane.
But there is no sign of compromise in his crusade against his officials speaking Russian.
He has also ordered all parliamentary hearings to be held in Kazakh, saying those who are not fluent must be provided with simultaneous translations.
His ministers will get no further leeway either.
“Next time I will report (from the cabinet) 100% in Kazakh,” privately owned news website Informburo.kz quoted Sagadiev as saying.