The early phase of schizophrenia is critical for rehabilitation outcomes: LAI antipsychotics can help in the clinical stabilization, but Evidence-Based Psychosocial Interventions (EBPI) are important to improve real-world psychosocial functioning. The present study aimed to assess the implementation and outcomes of EBPI in real-world clinical settings in people in the early phase of schizophrenia treated with LAI. Individuals diagnosed with Schizophrenia with an onset in the previous 5 years and stabilized with LAI treatment accessing 15 different centers were included in this prospective observation study with a 1-year observation follow-up. Rates of implementation of EBPI were recorded: participants receiving at least one EBPI were included in the “EBPI” group, and the others were included in the “Non-EBPI” group. Groups were compared on drop-out rates and clinical and functional outcomes at 3-, 6- and 12-months observations. A total of 116 participants were recruited in the study, 43 (37.07%) of which underwent at least one EBPI. A total of 68 (58.6%) participants completed the 1-year observation. No significant differences in drop-outs were observed between “EBPI” and “Non-EBPI” groups. Participants in the “EBPI” group showed superior improvements in real-world psychosocial functioning in longitudinal comparisons (12 months; p = 0.032) and at all time-points (all p < 0.05). Both groups showed improvements in core symptom domains, without other significant between-groups differences. EBPI are effective in improving psychosocial functioning in real-world clinical practice, but their dissemination is still limited. LAI antipsychotics are effective in clinical stabilization in the early phase of schizophrenia.