The move largely targets tariff-free petrol as some firms import more than they need and sell the excess, the Vientiane Times said.
This had led to a shortfall in government revenue, it added.
The newspaper quoted Lao government spokeswoman Bounpheng Mounphosay as saying that Vientiane will try to solve the problem by requiring "only necessary development projects'' to import tariff-free items.
Lao Deputy Planning and Investment Minister Bounthavy Sisouphanthong said officials would tighten up screening of authorised imports.
The newspaper did not specify where the imports came from but indicated that Thailand was a conduit.
Revenue collected at the Thai-Lao Friendship Bridge border checkpoint accounted for 2,330 billion kip (9.5 billion baht) last year. It could not reach government targets because of the tariff exemptions on various items, it said.