Preliminary studies, as well as the authors' own experience over a number of years, suggest a favorable role for immunotherapy using intravenous immunoglobulin (IVIG) and Humira in improving the success rate of in vitro fertilization (IVF) treatment in women suffering from recurrent implantation failure. IVIG down regulates in vivo and in vitro natural killer (NK) cell activity and modifies NK cell cytokine production profile. Compared to the literature on the application of IVIG in recurrent implantation failure patients, studies evaluating the use of the tumour necrosis factor-α (TNF-α) blocker Humira are scarce. The optimum method to prove the efficacy of therapeutic interventions is through conducting adequately powered and well-designed randomized controlled trials. Although the safety profile of immunotherapy has been demonstrated in several uncontrolled studies, further and larger studies including cost-effectiveness evaluation of the proposed interventions will need to be carried out.