Rudy X. Poelsterl, 51, beverage manager of the Washington Hilton Hotel who was active in masonic and German-American organizations, died Friday at Georgetown University Hospital following a heart attack.

He had been president of the Original Bavarian Dance Group of Washington for 17 years, and was a founder and served as president of the Gauverband Nordamerika (Organization of Bavarian Dance Clubs of North - America) during the early 1960s.

Mr. Poelsterl had danced with groups in folk life festivals sponsored by the Smithsonian Institution, the White House, West German embassy and at Wolf Trap.

He had been master of the Arminius Lodge of the Masons, had participated in the charitable activites of the clowns of the Almas Temple Shriners.

Mr. Poelsterl was a native of Germany and was a World War II combat veteran of the German Army.

He came to this country and Washington in 1957, and worked as a bartender for the Bavarian Restaurant in Washington prior to joining the Hilton in 1937. He was named beverage manager of the Washington Hilton in 1970.

He is survived by his wife, Mollie, and a daughter, Karen, both of the home in Washington; and a brother, Willi, of Munich, west Germany. CAPTION: Picture, RUDY X. POELSTERL