A massive knife was found in a car search in Kingsfold, police said.
Officers were tipped off by a local resident, and stopped the car in leafy Kingsfold near Penwortham.
The occupants were arrested for possession of two large knives that were found during a search, as well as drugs.
One of the knives, a large machete with a serrated edge, even came with its own sheath.
In March this year, Lancashire Constabulary participated in Operation Sceptre, a week-long nationwide knife amnesty designed to get knives off the streets.
A total of 182 knives were handed in in Lancashire during the amnesty.
Speaking about Operation Sceptre, Clive Grunshaw, Lancashire's Police and Crime Commissioner said: "Time and again we see the tragic impact on people's lives as a consequence of [knives] being used.
"Knives are deadly weapons and you will be arrested and prosecuted if you are caught carrying one."
Speaking in March, Det Ch Supt Neil Ashton, of Lancashire Police, said: “We know that over half of offences involving a knife happen in a private space and in most cases the offender was known to the victim, with a partner or family member often the perpetrator.
“We are committed to keeping our communities safe and tackling violent crime is a priority for us. We will continue to work 24/7 and 365 days of the year and to act on intelligence.”