The Mre11p/Rad50p/Xrs2p complex is involved in the repair of double-strand DNA breaks, nonhomologous end joining, and telomere length regulation. TEL1 is primarily involved in telomere length regulation. By an epistasis analysis, we conclude that Tel1p and the Mre11p/Rad50p/Xrs2p complex function in a single pathway of telomere length regulation.