In the title mol-ecule, C(12)H(13)NO(2), the dihydro-quinolinone fused-ring system is nearly planar [maximum deviation = 0.012 (3) Å], and the mean plane passing through the extended eth-oxy-methyl substituent is aligned at 86.9 (2)° with respect to the fused-ring system. In the crystal, adjacent mol-ecules are linked by an N-H⋯O(carbon-yl) hydrogen bond to generate a chain running along the b-axis direction.