The lasing characteristics of organic dyes of dicyanomethylene-pyran (DCM) substitutes have been studied at pumping with pulsed Nd-YAG-laser radiation at 1064 nm wavelength and 15-ns duration. Cavity parameters, concentration of active molecules, and pump level have been optimized to maximize the lasing efficiency. For efficient two-photon pumped upconverted lasing, organic molecules should possess not only high two-photon absorption (TPA) cross section, but also intense fluorescence, weakly subject to the concentration quenching due to aggregation and reabsorption. In addition, original design of a laser cavity is required to obtain maximum lasing efficiency in a weakly absorbing active medium. Among the compounds studied, the maximum lasing efficiency (higher than 0.5%) was obtained with the DCM molecule.