Back in the United States, Demeter was assigned to Texas League's Fort Worth Cats for the 1956 season. He hit home runs on four consecutive days from April 24 to 27, and six in his last seven games, a new league record. On May 20, he had a five-hit day that included his 10th home run of the season in a 17–4 victory over San Antonio. Demeter finished the year with 41 home runs and 128 RBI, both second only to minor league journeyman Ken Guettler, who had 143 RBI and shattered the Texas League record for home runs with 62. Demeter also was very busy in center field for the Cats, leading the league in putouts with 442. He was selected to the Texas League All-Star Team, receiving a scroll and a $100 check. Fort Worth General Manager Spencer Harris said, "He's ahead of Duke Snider at a similar stage in Duke's development."
