The present study examines a specific type of referee biases, home bias, and analyzes how the presence of fans affects home bias by using NBA games played in empty arenas during the COVID-19 pandemic in the 2020–2021 season and matches played before the pandemic from 2017 to 2020. This research also uses a unique data set from NBA Last Two Minute Reports to assess referees’ performance at the play level. The findings show crowd support does not cause referees to treat home and away teams differently in crucial situations during the NBA regular season, contrary to the results in most prior studies.