We show in this paper that it is possible to attain very high, including observable, values for the level of non-Gaussianity fNL associated with the bispectrum Bζ of the primordial curvature perturbation ζ, in a subclass of small-field slow-roll models of inflation with canonical kinetic terms. Such a result is obtained by taking care of loop corrections both in the spectrum Pζ and in the bispectrum Bζ. Sizable values for fNL arise even if ζ is generated during inflation. Five issues are considered when constraining the available parameter space: (1) We must ensure that we are in a perturbative regime so that the ζ series expansion, and its truncation, are valid. (2) We must apply the correct condition for the (possible) loop dominance in Bζ and/or Pζ. (3) We must satisfy the spectrum normalization condition. (4) We must satisfy the spectral tilt constraint. (5) We must have enough inflation to solve the horizon problem.