We report the observation of an isotriplet of excited charmed baryons, decaying into Lambda(c)(+)pi(-), Lambda(c)(+)pi(0), and Lambda(c)(+)pi(+). We measure the mass differences M(Lambda(c)(+)pi)-M(Lambda(c)(+)) and widths to be 515.4(-3.1-6.0)(+3.2+2.1)