Human chorionic gonadotropin (hCG) preparations have been widely used as a surrogate for the mid-cycle luteinizing hormone (LH) surge for several decades. The urinary source of hCG preparations was favored for many years because of the easy collection of the starting material. However, the final structure of these urinary-derived preparations appears to be quite different from the natural placenta product. Furthermore, many disadvantages of these commercial preparations have been reported, such as local adverse events and immunologic reactions. The recent advent of recombinant DNA technology has now made recombinant hCG (r-hCG) available. This new product ensures high purity and batch-to-batch consistency. The pharmacokinetic and pharmacodynamic profiles of both urinary and recombinant preparations are quite similar. In clinical practice, several trials have been performed to compare both the efficacy and safety of urinary hCG (u-hCG) and r-hCG preparations. Overall, the reported data show that r-hCG preparations are at least as effective as u-hCG products in reproducing the follicular events surrounding the endogenous LH surge. Moreover, the r-hCG products ensure a better hormonal environment during the luteal phase. Finally, the overall tolerability of r-hCG preparations has been shown to be much better than that of u-hCG preparations. As a consequence, the newly available r-hCG preparations offer the first opportunity for clinicians to treat anovulatory women with a full range of recombinant products.