Sperm functions are an important factor for fertility/pregnancy to be achieved. Sperm dysfunction is the most common cause of male infertility. The best option to help couples with such male factor to achieve a pregnancy, is using Assisted Reproductive Technology (ART), without defining the underlying cause of sperm dysfunction or male-factor infertility in general at the cellular and molecular levels. Thus, the limited success of ART in a proportion of male infertility cases is unsurprising. Ca 2+ signalling plays a fundamental role in the regulation of sperm function. Interestingly, it appears that the potential exists to diagnose abnormalities in the Ca 2+ channels that underlie sperm dysfunction. This raises the potential for future drug discovery to try to correct this defect by augmenting Ca 2+ signalling such as Ca 2+ store mobilisation or activating CatSper, as possible rational treatments for sperm dysfunction that may temporarily increase the capacity to interact with the egg. Such a pharmacological agent may provide a useful way of increasing the effectiveness of IUI or IVF over conventional IUI and IVF procedures.