We aimed to prospectively investigate the paternal antigen-induced cytokine secretion by peripheral blood mononuclear cells (PBMCs) in response to hormone treatment in women undergoing in vitro fertilisation (IVF) and to examine the predictive value of the cytokine secretion profile in the outcome of IVF treatment, in a pilot study. Twenty-five women were included and IVF treatment was successful for six and unsuccessful for 19 women. Blood samples were collected before IVF treatment, on four occasions during IVF and four weeks after embryo transfer. The numbers of Th1-, Th2- and Th17-associated cytokine-secreting cells and cytokine levels in cell supernatants were analysed by enzyme-linked immunospot-forming (ELISpot), enzyme-linked immune-sorbent (ELISA) or Luminex assay. None of the cytokines (IFN-γ, IL-4, IL-5, IL-10, IL-12, IL-13, IL-17, TNF and GM-CSF) had any predictive value regarding IVF outcome. The majority of the cytokines reached their peak levels at ovum pick-up, suggesting an enhancing influence of the hormonal stimulation. Pregnancy was associated with a high number of IL-4-, IL-5- and IL-13-secreting cells four weeks after ET. In conclusion, the results do not support our hypothesis of a more pronounced peripheral Th1 and Th17 deviation towards paternal antigens in infertile women with an unsuccessful IVF outcome, although this is based on a small number of observations. A larger study is required to confirm this conclusion. Higher numbers of Th2-associated cytokine-secreting cells in pregnant women four weeks after ET do corroborate the hypothesis of a Th2 deviation during pregnancy.