Travellers often present late for the third dose of hepatitis B vaccination and measuring anti-HBs serology is common practice to ensure that these individuals are protected. We assessed the adequacy of immune response in 86 healthy travellers who had their third dose of hepatitis B (HB) vaccine performed more than 1 year (median: 3.4 years; range: 1.1-10.5 years) after the second dose. Eighty-two travellers (95.3%) had evidence of sero-protection (anti-HBs titre >10 UI/L) including 16/17 (94.1%) travellers who had an interval of more than 5 years between second and third vaccine dose. We did not find any risk factor associated with insufficient response.