Prime Minister Jean-Max Bellerive of Haiti says the death toll from the earthquake on 12 January 2010 is more than 316,000.
On the first anniversary of the disaster, he has raised the figure from previous estimates of about 250,000 killed when the quake struck at 4.53pm (local time).
Mr Bellerive said the recovery of additional bodies over the year had put the total figure at "over 316,000 people killed".
Memorial services were held around the country on Wednesday.
One ceremony at the ruins of the National Cathedral in Port-au-Prince was conducted by the Papal envoy to Haiti.
Radio stations played solemn music and shops, businesses, banks, schools and government offices were closed.