In the suit, which was filed Monday in King County Superior Court, the drivers say Uber provides the same service as taxis but doesn't have to abide by the same safety and financial regulations.
"Uber is not playing by the rules like the rest of us are, and local, small business owners like myself and our families are suffering as a result," Parminder Cheema, a taxi driver and union official, said in a Monday news release. "The community is at risk as well. If things don't change, somebody might get hurt."
The complaint alleges Uber drivers are not subjected to the same safeguards, requirements and penalties. It also claims Uber is violating state laws that regulate privately operated limousine services.
The lawsuit comes just a week after the Seattle City Council approved new rideshare regulations and put a cap on the number of rideshare drivers allowed in the city. That measure will become law 30 days after Seattle Mayor Ed Murray signs it.