Stimulated emission pumping (SEP) experiments were performed on propynal (H-C=C-CHO). The SEP spectra probed the overtones of the pure C=O stretch (nu4) and a combination of the C=O stretch with the C=C-C bend (nu9). Term energies for J less-than-or-equal-to 8, K less-than-or-equal-to 2 of the vibrations 4(2), 4(3), 4(4), 4(5), 4(3)9(1) as well as two unidentified perturbing vibrational states were obtained. The SEP spectra show simple rotational structure that is assignable by means of a near prolate asymmetric top model. Rotational constants were obtained for all the vibrational states measured. Spectroscopic perturbations are observed for nu4=2,4,5 as either anomalous rotational constants, anomalous energy level shifts, or as extra spectral transitions. Complex state mixing is not observed at the current spectroscopic resolution (0.04 cm-1) even though vibrational state densities as high as 400 states per cm-1 were probed. The propynal SEP results are compared to other SEP experiments on aldehyde containing molecules and inferences are made.