The purpose of this research was to investigate the potential relationships between self-regulated learning with regard to instrument practice, amount of instrument practice time, and Big Five personality traits. Participants were 172 preservice teachers enrolled in music teaching undergraduate programs of three universities in Turkey. Data were collected via a demographics questionnaire, musical behaviors questionnaire, the Big Five Inventory (BFI), and the Self-Regulated Learning in Instrument Practice Scale (SRLIPS). BFI includes neuroticism, extraversion, openness, agreeableness, and conscientiousness dimensions, and SRLIPS has forethought, performance, and self-reflection dimensions. The results revealed that preservice music teachers' last exam grade and daily practice hours on their main instrument and SRLIPS scores did not differ significantly by their year of study. Participants' last exam grades correlated significantly with their scores on the dimensions of conscientiousness, forethought, performance, and self-reflection. Daily practice hours correlated with the dimensions of conscientiousness, forethought, and performance. Years of playing the main instrument correlated significantly with performance dimension. Moreover, each SRLIPS dimension correlated significantly with each dimension in the BFI. Regression analyses revealed that forethought and self-reflection were predicted by conscientiousness and performance scores were explained by openness. Finally, last exam grade was predicted by forethought and conscientiousness dimensions.