Police, equipped with semi-automatic firearms, surrounded a house in Upper Mounts this morning (Tuesday).
Eyewitnesses reported seeing armed officers using battering rams as they surrounded a property in St Michael's Road earlier today.
There were around 15 officers and four emergency vehicles, as well as an ambulance.
Road closures were also in place and the police helicopter circled above.
A spokesman for Northamptonshire Police said: “We are currently executing a planned drugs warrant at an address in St Michael’s Road, Northampton.
"Officers are expected to be there for the next hour with the road closures to be lifted shortly afterwards. There is no risk of harm to members of the public.”