The Boston statistics are included in a national report on clerical abuse to be published on Friday.
"As I present this information to the people ... I apologise once again to all who have been hurt so grievously by priests and the bishops who were responsible for supervising them," said Boston Archbishop Sean O'Malley.
"The numbers are truly horrific, but they are also telling both in terms of extent of the problem and the time frame in which the magnitude of the problem became known," O'Malley said.
The number of accused priests represents approximately 7% of the 2,324 who served in the Boston archdiocese from 1950-2003. The largest group was ordained in the 1960s.
O'Malley stressed that 162 was the total number of priests against whom allegations had been made.
'Many priests deceased'
"It does not mean that a determination criminally, civilly, or canonically, has been made regarding the truth or non-truth of the allegation," he said.
Some 58 of the accused priests are now deceased.
Of the 815 alleged victims, slightly more than half related to sexual abuse alleged against just seven priests.
With some two million Roman Catholics, the Boston archdiocese is one of the largest and most influential in the United States, and has paid $120.6 million through December 2003 in settling sexual abuse claims.
O'Malley was installed as the head of the archdiocese in August, replacing Cardinal Bernard Law who resigned in December amid repeated allegations of complicity in covering up the abuse scandal.