Novel drug availability has increased the depth of response and revolutionised the outcomes of multiple myeloma patients. Minimal residual disease evaluation is a surrogate for progression-free survival and overall survival and has become widely used not-only in clinical trials but also in daily patient management. Bone marrow aspiration is the gold standard for response evaluation, but due to the patchy nature of myeloma, false negatives are possible. Liquid biopsy and blood-based minimal residual disease evaluation consider circulating plasma cells, mass spectrometry or circulating tumour DNA. This approach is less invasive, can provide a more comprehensive picture of the disease and could become the future of response evaluation in multiple myeloma patients.