Abstract Background and Aims Primary membranous nephropathy (PMN) is the most common cause of nephrotic syndrome (NS) in adults and is currently considered an autoimmune-related disease. B cell depleting treatments, currently the most commonly used is rituximab, are usually effective in treating membranous nephropathy (MN). However, about 35% of patients treated with rituximab fail to respond, and relapses after RTX-induced remission are frequent. Among the new anti-B cell therapeutics, obinutuzumab has shown significant efficacy in treating refractory MN, including those that have failed treatment with RTX. The literature on the clinical efficacy of obinutuzumab as an initial treatment for MN is very limited. This study aimed to evaluate the efficacy and safety of obinutuzumab as an initial treatment for PMN. Method We reviewed all patients (n = 6) with PMN diagnosed by renal biopsy who were followed up for ≥3 months and received obinutuzumab as initial therapy at our center. We analyzed the trend of changes in related indicators such as urine protein, serum albumin, serum creatinine, serum PLA2R antibody, B lymphocyte count, and the response time and remission rate. Results After obinutuzumab therapy, all patients achieved remission at a median follow-up of 3 months (IQR, 2.5–3.25 months). The remission rate at three months was 83.3%. Two patients experienced adverse reactions in our study: one had interstitial pneumonia and eczema, and one had transient leukopenia. Conclusion As the initial treatment for primary membranous nephropathy, obinutuzumab induces a safe and rapid response. Large prospective studies are needed to provide more evidence.