We used human papillomavirus type 16 (HPV-16) particles composed of capsid proteins L1 and L2 (L1/L2 capsids) as an antigen to produce mouse monoclonal antibodies (MAbs). Of 18 MAbs recognizing surface epitopes of L1/L2 capsids, 1 was an anti-L1 MAb and 17 were anti-L2 MAbs. Seven of 11 anti-L2 MAbs recognizing linear epitopes wer found to bind to a synthetic peptide with an HPV-16 L2 sequence of amino acids (aa) 69-81, which is within a highly conserved region among different HPVs. The synthetic peptide reacted with the human sera that had been shown to be positive for an antibody against HPV-16, -18, -58, or -6b capsids composed of L1 alone. The data suggest that the HPV-16 L2 region of aa 69-81 contains a type-common immunodeterminant exposed on the surface of HPV virions.