The network structure of radiation-cross-linked solutions of star molecules is analyzed theoretically and experimentally. We synthesize gels via electron beam irradiation of aqueous solutions of high-functionality (f > 30) star PEO in the concentration regime where the molecules exhibit extensive overlap. The expected network properties of the resulting gels are systematically varied by using PEO stars with different arm lengths and functionalities and by adjusting the irradiation dose and initial polymer concentration. The cross-link density in these gels is analyzed three ways : (1) elastic modulus, (2) swelling equilibrium, and (3) comparison to the cross-link density of linear gels prepared in a comparable fashion. In order to predict the network structure of cross-linked star molecules from swelling, Flory’s equilibrium swelling theory is modified to include a bimodal distribution of cross-link functionalities. The modified equation fits the trends in swelling behavior of the series of radiation-cross-linked star PEO gels. The apparent cross-link density of radiation-cross-linked star PEO gels obtained by physical property measurement-swelling and elastic modulus-differ from the cross-link density expected based on comparison to linear gels cross-linked under identical conditions. Cross-link densities based on the elastic modulus are lower than the expected values, suggesting that a significant fraction of elastically ineffective cross-links form between star af ms within the same molecule.