Effective mentoring of EFL preservice teachers may advance EFL teaching practices. Five factors for mentoring have been identified, namely, personal attributes, system requirements, pedagogical knowledge, modeling, and feedback. An empirically based survey instrument focused on 106 Vietnamese preservice teachers' perceptions of their mentoring for EFL teaching across these five factors. Apart from acceptable Cronbach alphas for four of the five factors (system requirements was 0.08 below the accepted 0.70 level), analysis revealed that more than 50% of these preservice teachers perceived that they had not received mentoring for developing their teaching of English writing on 29 of the 34 survey items. Mentoring practices in this study varied; consequently, EFL mentors may require guidance for enhancing their practices. In addition, the instrument linked to the five-factor mentoring model may assist in identifying mentors' needs for devising professional development programs.