Treatment of advanced PCLs is limited and rarely reaches complete remission despite aggressive treatment modalities, such as polychemotherapy with various adverse effects. However, several monoclonal antibodies drug agents in patients with advanced primary cutaneous lymphomas demonstrate promising efficacy and manageable safety profiles. The monoclonal antibodies drug agents have favourable tolerability compared with multi-agent cytotoxic chemotherapy. However, adverse effects manifest with a broad clinical spectrum, hence the markers of targeted therapies are not limited to tumour cells but found on tumour cells and also on benign T and/or B cells. Moreover, the safety profile and direct causal association of drug and adverse effects should be interpreted with caution because many of the patients in clinical studies have received multiple treatments. Here, we focus on the safety profile of mAbs therapies that have recently been approved or are currently under preclinical or clinical investigation for CBCLs (rituximab) and CTCLs (brentuximab, mogamulizumab, and alemtuzumab). Further studies to define clinical safety profile in the patient cohort with cutaneous lymphomas are needed.