A medical diagnosis support device of an embodiment includes processing circuitry. The processing circuitry acquires first reference data based on first clinical data relating to a diagnosis result of an evaluation target and second reference data based on second clinical data relating to a comparison target diagnosis result for the evaluation target and performs an analysis process relating to the diagnosis result of the evaluation target based on the first reference data and the second reference data. The first reference data includes first data that has been referred to by a first user to obtain the diagnosis result of the evaluation target and second data that has been referred to by a diagnosis support system to obtain the diagnosis result of the evaluation target. The second reference data includes the first data that has been referred to by at least one of the first user and a second user different from the first user in order to obtain the diagnosis result of the comparison target.