A case report of dual sexual transmission, with secondary transmission from naïve to naïve patient, of HIV harbouring K103N and L100I mutations, conferring full non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance, plus 2 nucleoside analogous reverse transcriptase inhibitor (NRTI) mutations is described. The secondary transmission of the resistant virus was confirmed by phylogenetic analysis. Data also suggest that mutations related to NRTI and NNRTI resistance may persist for a long time in naive patients, over 2 years in the present case report.