Next to motivation and foreign language aptitude, personality is regarded as the most influential factor on SLL success. Conceptualizing personality on the basis of the Big Five construct, this thesis sets its primary focus on the factors extraversion and conscientiousness and examines possible associations with Second Language Learning of English. Conscientiousness has been found to enhance achievement in both work-related and academic contexts. Extraversion had for a long time been expected to have enhancing effects, however, positive effects have been found solely for speaking-related learning and performance. In order to investigate possible associations between personality and SLL, questionnaire data was collected from a total of n=242 probands. Personality was measured by means of the NEO-Five Factor Inventory, a commonly used 60-item personality questionnaire. SLL-specific items were constructed by the researcher. Results of correlations confirm the scientifically established positive association between the trait conscientiousness and course grades. In line with the literature on the topic, extraversion was not found to correlate with overall course grades. Interestingly, however, the qualitative analysis of student and teacher beliefs showed that the exact opposite is true of subjective perceptions: while both samples believe that conscientiousness influences English grades and L2 progress positively, they are convinced that extraversion has an even stronger positive effect. Finally, one particularly interesting finding is that the different forms of skill enjoyment (i.e. speaking, listening, reading and writing at school vs. in private time, respectively) correlate significantly positively with one another, indicating that there is an underlying dimension of “general L2 learning motivation” for the enjoyment of using and practicing the second language, independent of skill or context.