In a decision that could have a major impact on the case, a judge ruled Thursday that Bill Cosby will face five additional accusers at his retrial on sexual assault charges that is to begin in April.

The decision means that, in addition to Andrea Constand, a former Temple University employee who says Mr. Cosby drugged and sexually assaulted her at his home near Philadelphia in 2004, the jury will hear from five other women who have similar accusations against Mr. Cosby.

This puts considerable pressure on Mr. Cosby, 80, whose first trial ended in a hung jury last summer. He faced only one accuser other than Ms. Constand during that trial, Kelly Johnson, and her testimony was often hesitant.

Prosecutors had asked Judge Steven T. O’Neill to admit testimony from 19 additional women for the retrial. But experts said that, even with only five permitted to testify, prosecutors will have a greater ability to convince jurors that the alleged assault on Ms. Constand, which Mr. Cosby denies, was part of a pattern of sexual misconduct that stretched over several decades.