In the summer of 1981, Otto played three friendly games for English side Middlesbrough, with a view to a permanent transfer. He impressed manager Bobby Murdoch and signed a two-year contract in August. He made a scoring debut in the Football League, against Tottenham Hotspur at Ayresome Park, but the team lost 3–1. Otto was joint top scorer with a meagre five goals when Middlesbrough dropped into the Second Division in 1982. He stayed at the club for the next few seasons.