Oncolytic immunotherapy is a novel and promising approach in clinical oncology practice. Currently, immune checkpoint inhibitors (ICIs) are the first-line treatment options for disseminated melanoma. Nivolumab is a well-defined ICI that blocks programmed cell death 1 (PD-1) and mainly increases anti-tumor immunity. The opportunistic infections are not expected with ICI therapies due to their immune reactivation effects. To date, only a few cancer patients have been reported with activated TB during ICI therapy. Here, we presented a young female patient diagnosed with histologically-confirmed tuberculous lymphadenitis while on nivolumab therapy for metastatic melanoma. The current case report represents the first described tuberculous lymphadenitis case related to anti-PD-1 based monoclonal antibody therapy. The mechanism underlying the development of TB with PD-1 inhibitor use has not been illuminated yet. Triggering of excessive inflammatory responses with ICIs therapy is a potential cause. Considering the increased utilization of ICI-based immunotherapies, the TB screening should be considered in all patients before starting PD-1 inhibitor therapy.