The current study aims to identify and analyze the perceptions that a group of primary school inservice teachers with specialty in Spanish language and Mathematics (n 98), belonging to the Usulutan Department (El Salvador, Central America) have about what competencies should characterize a good teacher of this educational level. The participants were beneficiaries of the Luxembourg project that intended to strengthen the teachers' professional development to improve their teaching practice. This was made within the teachers' qualification program that was promoted by the Ministry of Education of El Salvador with the support of the Grand Duchy of Luxembourg. Due to the homogeneous nature of the sample (683 in-service teachers), an intentional non-probabilistic sample method was applied in order to obtain the calculation of the sample. The data was obtained through a survey with questions and answers using the Likert scale which let to group the gathered information in three competency dimensions derived from the ones determined by the Tuning America Latina (Beneitone et al., 2007) and the taxonomy about educational competencies elaborated by Perrenoud (2004). The results, as well as the findings obtained with other studies regarding what a primary school teacher must know and do to work successfully, show a high percentage of agreement among the participants. These results will be of great importance to the reformulation and improvement of the syllabi of the teacher training programs in El Salvador (Central America) as well as being used eventually in international comparative studies.