ABSTRACT Background Information on the effect of the paliperidone palmitate three-month (PP3M) formulation on functionality in patients in the early stages of psychosis is lacking. The primary aim of this study was to evaluate the impact of PP3M on functionality in patients recently diagnosed with schizophrenia. Research Design and Methods This was an observational, multicenter, and prospective study in patients with a recent diagnosis of schizophrenia undergoing treatment with PP3M. Evaluations included the Personal and Social Performance (PSP) scale, the Clinical Global Impression-Schizophrenia (CGI-Sch), the Medication Satisfaction Questionnaire and the Involvement Evaluation Questionnaire. Results A total of 101/110 evaluable patients (91.8%) completed the study and were included in the efficacy analyses. The total PSP score increased from a mean of 68.5 (15.3) at baseline to a mean of 72.1 (15.4) at month 6 and 74.8 (16.7) at month 12 with a before-and-after difference of 3.6 (95% CI, 1.6 to 5.5, p < 0.001) at month 6 and 6.2 (95% CI, 4.2 to 8.3, p < 0.001) at month 12. CGI-Sch severity significantly decreased from a mean score of 2.8 (1.1) at baseline to a score of 2.2 (1.1) at month 12 with a before-and-after difference of −0.6 (95% CI, 0.8 to −0.4, p < 0.001). Conclusions Early introduction of PP3M in the course of schizophrenia is associated with a meaningful benefit in social functioning and at least maintains clinical stability.