A man has been arrested after dozens of officers including armed police swooped on addresses in Winchburgh, Uphall, Philipstoun and Bridgend.
The operation was part of enforcement activity into organised crime, and police say investigations are continuing with a positive line of enquiry.
Various weapons including a crossbow and bolt, an axe, a dagger and hunting knife were found in an address in Church Court, Philipstoun, along with a quantity of cannabis.
During the search of a property in Glebe Place, Uphall, air weapon gas canisters were seized, while at a home in Castle Terrace, Winchburgh, police seized small quantities of cannabis and various pieces of cultivation equipment.
The search of a house in Auldhill Entry, Bridgend, on Thursday resulted in the arrest of a 30-year-old man, who is due to appear at Livingston Sheriff Court on Monday, October 1.
Detective Inspector Paul Batten said: “After intelligence was received relating to illicit items, including weapons and drugs, being within a number of West Lothian homes, swift enforcement action was carried out resulting in these recoveries and the arrest, so far, of one man.
“Our inquiries are continuing and the public can rest assured that all resources at our disposal will be utilised as we continue to target those linked to organised crime in West Lothian.
“If you have information relating to ongoing criminality within your community you can report this to us via 101 or make an anonymous report to the charity Crimestoppers on 0800 555 111.”