Abstract: This study sought to determine the degree of prediction of some motivational factors on the performance of adult French learners. Specifically, the influence of the following motivational factors were examined: Perception of needs, job placement and attitude to French language. An ex-post-facto research design was used in the study. Three hundred and fifty-four first year adult learners from 9 adult French learning centers in Oyo, Ogun and Lagos States were selected purposively for the study. Data was collected using 3 instruments, a French language Attitudinal Scale (FLAS), a Questionnaire on Motivation for French Learning (QMFL) and a French Language Performance Test (FLPT). Essentially, the data were subjected to multiple regression analysis. From the results, it was discovered that the selected motivational variables viz; perception of needs, job placement and attitude to French language, actually have a high predictive value for adult learners� achievement in French language. Learners� attitudes to French language stand out as the most significant variable in predicting performance of adult French learners. Implications of these findings for motivating adults to learn are discussed in the study.