The troubled basketball star was pulled over on the motorway in his white Mercedes 4x4 for going too slowly and was taken to a nearby police station by the California Highway Patrol and held on $15,000 bail.
Police say that the NBA player had been driving in a "serpentine manner", TMZ reports.
Lamar initially ignored the authorities and drove past three exits before coming to a stop, at which point he "showed obvious signs of intoxication".
Lamar recently resurfaced in LA after days with his whereabouts unknown. The troubled athlete was spotted picking up some lunch at a drive-thru earlier this week before heading to the house he shares with his reality star wife Khloé.
He seemed in good spirits – and made a point of showing photographers that his wedding ring was still in place.
Dressed in a grey t-shirt and a red baseball cap, he smiled from behind the wheel of his car as he drove back to the marital home in Tarzana. It was reported that Lamar returned to address some serious issues, including alleged drug addictions.
His loyal wife Khloé, 29, is said to be determined to help her husband of four years get his life back on track. On Monday, she was also spotted wearing her wedding ring.
The youngest Kardashian sister has remained tight-lipped since stories of her husband’s alleged addictions, and infidelities, first surfaced.
And just a few days ago, she seemed to make reference to the numerous stories being written about her marriage, angrily writing, "Really hard to sit here and listen to people talk s--- about my family …I’m too protective for this s---!"
Khloé is desperate for 33-year-old Lamar to seek help – and for his part, a source close to the sports star told TMZ he is "open to reason and listening to the people who love him the most."
Among those rooting for Lamar and Khloé is her sister Kim Kardashian. Khloé only recently revealed Lamar's struggles with substance abuse to her family, and they are all rallying round.
A source told E! that Kim was "shocked" to learn of her brother-in-law's problems, and is being "very supportive".
"She only wants what's best for Khloé," the insider added.
New mum Kim "would like to see them work it out. She knows how much they love each other. Everyone in the family feels like divorce should be the last option."