Recently, cases of severe respiratory illness in military and civilian populations have been associated with a new genomic variant of adenovirus (Ad) serotype 14, designated Ad14a. Compared to the Ad14 reference strain (de Wit), this new virus had a deletion of two amino acid residues in the fiber protein knob. Here we tested whether this mutation changed receptor usage of Ad14a compared to Ad14-de Wit. Competition studies with radio-labeled viruses revealed that both Ad14-de Wit and Ad14a used the same receptor which is hitherto unknown. We also found that recombinant fiber knobs only partially blocked attachment of Ad14a, indicating that virus capsid proteins other than the fiber are involved in infection.