The re-invasion of Okinawa by the Bactrocera dorsalis complex (oriental fruit fly and its relatives) after its eradication was comprehensively documented for the first time. From 1987 to 2008, more than 300 adult flies were captured by monitoring traps baited with methyl eugenol, showing frequent re-invasion. During this period, re-colonization (detection of infested fruits) occurred six times; in all cases the flies were successfully re-eradicated by countermeasures (mainly male annihilation method). This indicates that the oriental fruit fly problem in Japan has not been resolved and that the flies should be monitored and counteracted continuously. By summarizing the re-invasion data, we found interesting geographical patterns. Adults were more frequently trapped in the southern area (Sakishima Islands, SI), while colonization occurred more frequently in the northern area (Okinawa Islands, OI). Annual trap catches increased in SI, but not in OI. In SI, adults were trapped most frequently in summer, whereas peak catches in OI were observed in autumn. These results demonstrate that the invasion pattern in OI is independent from that in SI. One possible explanation for the observed geographical differences is that it reflects the difference in invasion causes.