David Primis, a former sales manager of the Prudential Insurance Company of America, died of cancer yesterday at his home in Valley Stream, L.I. He was 73 years years old.

Mr. Primis had been with Prudential for 40 years.

When he retired in 1974, he established his own insurance brokerage, the Union Brokerage Company, in Valley Stream.

He is survived by his wife, the former Sybil Schiller; a daughter, Sondra Plotkin of Far Rockaway, Queens, and two sons, Dr. Ronald A. Primis of East Meadow, L.I., and Lance R. Primis of Holmdel, N.J. He also leaves two sisters, Miriam Berr of Brooklyn, and Sylvia Sussman of North Hollywood, Calif.; two brothers, Abraham Primis of Brooklyn and Nathan Primis of New Windsor, N.Y., and seven grandchildren.