Nicola Sturgeon said triggering Article 50 was a leap in the dark
The Scottish First Minister spoke out after a letter informing European Union officials of the UK’s intention the leave the bloc was handed to European Council President Donald Tusk.
Ms Sturgeon said she hoped Brexit "goes well" but predicted the formal triggering of Article 50 would bring "a lot of concerns for a lot of people".
Nicola Sturgeon meets Theresa May for talks in Glasgow
She said: "There is no doubt that what is happening today does represent something of a leap in the dark.
"Some nine months after the EU referendum, the prime minister still can't answer basic questions about what Brexit will mean for businesses, for the economy generally, and for the type of society we live in."
Ms Sturgeon said the Scottish government would look to focus on Scotland being a "great place to do business" despite Brexit.
But the first minister, who met Mrs May for talks in Glasgow on Monday, said there had been no commitment from the UK government that powers over areas such as fishing and agriculture would be returned to Holyrood rather than Westminster after Brexit.