Uber chief executive Travis Kalanick will take a leave of absence for an unspecified period and let his leadership team run the troubled ride-hailing company while he is away.
Mr Kalanick told employees about his decision in a memo today.
He says he needs time off to grieve for his mother, who died in a boating accident in May.
He also says he is responsible for the company's current situation and needs to become a better leader.
The announcement comes as former US attorney general Eric Holder released a list of recommendations to improve Uber's toxic corporate culture.
Mr Holder's firm was hired to investigate Uber's workplace after a former engineer exposed rampant sexual harassment within Uber's ranks.