Solving problems associated with reproductive failure in sow herds can be a challenge. It is critical to meet breeding targets on a routine basis, and to achieve the appropriate farrowing rates and litter sizes. Reproductive failure interferes with the consistent production of pigs, which ultimately results in the suboptimal number of pigs for market. This chapter will highlight some of the factors affecting reproductive efficiency, including gilt development, litter size, control of the weaning to oestrus interval and seasonal infertility. Attention is given to various management strategies which help producers to continue to be profitable.