Results are presented from a search for large, extra spatial dimensions in events with either two isolated muons or two isolated electrons. The data are from proton–proton interactions at View the MathML source collected with the CMS detector at the LHC. The size of the data sample corresponds to an integrated luminosity of approximately 2 fb−1. The observed dimuon and dielectron mass spectra are found to be consistent with standard-model expectations. Depending on the number of extra dimensions, the 95% confidence level limits from the combined μμ and ee channels range from Ms>2.4 TeV to Ms>3.8 TeV, where Ms characterizes the scale for the onset of quantum gravity.