Romanian educational system is in a constant search for reform, due to one of the highest rates of students' underachievement in basic skills and lack of qualified teachers among EU member states. It is well established that professional learning communities (PLCs) can be a solution for both problems, aiming to enhance students' results by teacher collaboration in learning and professional development. This study aims to determine the specificity of Romanian PLCs in relation with some contextual factors - school size, school environment (urban or rural), type of school (general or special school), professional development procedures at school level, and the individual factors that can impact the PLC, represented by teachers' personality structure. To answer the research question, reflecting on what contextual and individual factors determine the specificity of PLCs, two online questionnaires and a demographic survey were distributed to teachers across Romania. First, the School Professional Staff as Learning Community Questionnaire (SPSLCQ) was validated on the 253 participants, the original five-factor structure of SPSLCQ adequately fit the sample and proved to be a reliable instrument in the Romanian population. The results showed the Romanian PLCs' do not significantly differ from other countries: the most representative PLC dimension is shared vision, the organizational factor which explains best the PLC is the existence of strong at-school-level professional development procedures. School size best describes the differences between PLCs, but they do not differ in terms of school environment and school type. The personality factor that correlates the most with PLC is conscientiousness, but the correlation is non-significant. These results suggest that for functionally stronger PLCs, the school should implement professional development procedures at school level, based on collaboration and mutual learning in small groups of teachers.