Lasing emission with whispering gallery modes is achieved for microcavities of thiophene-phenylene co-oligomers embedded in Si/SiO2 substrates. The microcavities show a lasing threshold that is 20-50 % of the values observed for bulk films. Quality factors of a few thousand are achieved for these structures. The grain boundaries and cracks in the film at the circumferential interface are thought to limit the quality factor and lasing threshold of these microcavities.