This paper clarifies the meaning of ‘the full number of the Gentiles’ in Romans 11:25. Two interpretation methodologies are to be used. First, it is the Greco-Roman rhetoric that Paul used, especially the forensic rhetoric approach, which will bring to light Paul's rhetorical techniques and strategies concealed in Romans 9-11. Secondly, this is a approaching method of geographic spatial concept. Romans 15:18-21 pertains to the places where the apostle Paul preached the Gospel in person. Thus, the number of Gentiles inhabiting the actual regions and cities (Mediterranean coast) should be interpreted through a geographical point of view and a physical spatial concept. The meaning of ‘the full number of the Gentiles’ in Romans 11:25 falls into three hypotheses:

1. The number of Gentile Christian communities who confessed Jesus as the Messiah.
2. The number of those who came to faith hearing the Gospel among the Gentiles in the places where Paul preached.
3. The number of Gentiles who heard the Gospel – regardless of their faith.

This paper will contend for the validity of the third hypothesis. The full number of the Gentiles corresponds to the number of the Gentiles inhabiting Jerusalem to Illyricum where Paul itinerated to preach the Gospel in person. In addition, in light of its connection to Romans 15, this paper brings to light that ‘the full number of the Gentiles’ is closely related to Paul's fund-raising (Romans 15:19-21, 24-29).