The two men picked up the workers in the area of Fifth and Waverly avenues in Redwood City around 9:20 a.m. Friday, police Agent Dan Ryan said.
"That's where a bunch of day laborers gather every day, apparently," Ryan said.
The two men told the laborers they had three separate jobs in Palo Alto, but that the homeowners at the job sites did not want cell phones on the job. They demanded the three workers' cell phones and their wallets, saying they needed to borrow the workers' identification to verify they could work.
After the workers handed over those items, the suspects said they needed to pick up tools and supplies.
The workers were left at three separate "job sites" to wait for the men, who never returned, according to Ryan. The suspects made off with the cell phones and about $400 in cash.
Ryan said the crime is considered a grand theft by con, an act he described as "despicable."
"Often times these day workers are victimized," Ryan said.
Ryan said there are some cases in which laborers work an entire day and then don't get paid.
The suspects are described as Hispanic males in their mid-30s, both about 5 feet 7 inches tall and weighing 160 pounds. Their vehicle is a bluish-gray, four-door sedan, Ryan said.
Anyone with information on the crime or the suspects should call the Police Department's anonymous tip line at (650) 329-2190.