While the value of social capital for teaching seems paramount, a crucial question is how to shape the necessary learning climate that allows beginning pre-service teachers to build and access such social capital. A total of 321 pre-service teachers from Barcelona participated in a survey including social network questions, climate scales, and performance data. Findings reveal a significant relationship between pre-service teachers' social capital and performance as well as professional competence. Also, results show that a collaborative and innovative climate is positively related to pre-service teachers' performance and professional competence as mediated through student's social capital. Thus, social capital plays a mediating role by explaining the relationship between a supportive learning climate in internship schools and pre-service teachers' performance.