The negative emotion of Foreign Language Classroom Anxiety (FLCA) and the positive emotion of Foreign Language Enjoyment (FLE) have both been linked to foreign language (FL) learners’ Self-Perceived Proficiency (SPP). In linear correlational studies, SPP has been found to be negatively affected by FLCA and positively affected by FLE. However, linear correlational research methods are limited in the extent to which they can depict these interrelations. In this study, we examined how different levels of FLCA and FLE influenced SPP in concert in a sample of n = 1039 FL learners by utilising polynomial regression with response surface analysis. The response model generated visually depicted a complex SPP pattern as a result of differing levels of FLCA and FLE. This three-dimensional model provides considerable insight into the interaction of positive and negative emotions above and beyond what could be derived from ‘classical’ methods of correlation and linear regression.