The economy had contracted by 2.2% in the first three months of the year, but a sharp increase in construction and mining powered a rebound from April to June, the Central Statistics Office said.
Compared to the second quarter of 2010, the economy grew by 12.4%.
The country's first-ever national strike by civil servants had hobbled the country for eight weeks, until the labour action was suspended on June 11. But that was offset by the strong jumps in construction and mining activity.
"The increase was mainly from construction and mining sectors, which increased by 28.3% and 23.7% respectively," it said.
Mining accounts for about 30% of Botswana's economy, but the government is pushing to diversify the economy away from exporting only rough stones.
A deal with De Beers was announced last month for the world's leading diamond company to move its rough stone sorting and trading division from London to Gaborone.
The African Development Bank predicts Botswana's economy to grow by 6.9% this year.