Aim: The aim of this study was to design, validate, and assess the effectiveness of the MiNa scale in measuring mindfulness and its impact on young students’ mental health and holistic development, with a focus on diverse educational needs. Materials and Methods: This study utilized a mixed-methods approach to validate the MiNa Questionnaire. Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) were conducted on a sample of 224 students from Greece and Cyprus, who completed the questionnaire. Psychometric properties, including reliability and validity, were also assessed using standard statistical methods. Results: EFA revealed a three-factor structure explaining 53% of the variance, with strong factor loadings and reliability (Cronbach’s α > 0.7). CFA further confirmed the model fit, with RMSEA = 0.03, CFI = 0.97, and SRMR = 0.08. The results indicated significant improvements in students that attended mindfulness interventional programs, especially on their emotional regulation, and cognitive focus. It is important to note that positive results were predominantly observed among the sample of students characterized by vulnerability. Conclusions: The MiNa Questionnaire has proven to be a reliable and valid tool for assessing mindfulness in students from diverse educational backgrounds. Its adaptability for students with disabilities, combined with its cultural inclusivity, makes it a valuable resource for educators seeking to implement mindfulness programs in varied educational contexts.