We investigate prospects for indirect detection of Kaluza-Klein dark matter, focusing on the annihilation radiation of the first Kaluza-Klein excitation of the hypercharge gauge boson B-(1) in the galactic halo; in particular we estimate neutrino, gamma-ray and synchrotron fluxes. Comparing the predicted fluxes with observational data we are able to constrain the B-(1) mass (and therefore the compactification scale). The constraints depend on the specific model adopted for the dark matter density profile. For a Navarro, Frenk, and White profile the analysis of synchrotron radiation puts a lower bound on the B-(1) mass of the order of similar or equal to300 GeV.