The present invention features methods of evaluating the fertility of a female subject, or the fertilization competence of an oocyte extracted from an ovarian follicle, using measurements of one or more differentially expressed components of follicular fluid. The methods of the invention include the steps of measuring the level of a component of follicular fluid. Examples of components of follicular fluid useful in the methods of the invention include apolipoprotein IA, apolipoprotein A, apolipoprotein B, apolipoprotein E, prothrombin, CD 133 (prominin), alpha-2 macroglobulin, alpha crystallin B chain, ATP synthase alpha chain, neuropilin, heparin, heparin-like molecules, heparin receptors, bile acids, Aid, CS, Cortisol, Ang1, Ang2, cholesterol and its derivatives, cholesterol receptors, phospholipids, HDL, LDL, VLDL5 chylomicrons, retinoids, carotenoids, retinol-binding proteins, retinoic acid receptors, transthyretins, leptin, fibrin, ADPases, metal ions, and cytokines, e.g., IL-1β, IL-4, IL-5, IL-6, IL-8, IL-IO, IL-12p40, IL-12p70, IL-13, VEGF, VEGF receptors, PlGF, INF-γ, Aid, CS, Ang1, Ang2, TNF-α, C-reactive protein, and angiopoetin, and comparing the measured level to a reference range in order to determine whether the subject is likely to be fertile, or whether the oocyte is likely to be fertilization-competent. The invention also features methods of treatment of an infertile subject, wherein the treatment methods utilize measurements of one or more differentially expressed components of follicular fluid to determine optimal conditions for performing assisted reproductive therapy, e.g., in vitro fertilization.