Organic light emitting diodes (OLEDs) have been fabricated from organic semiconducting polymer nanospheres (SPNs) which have been deposited from aqueous dispersions. The active layer of the devices consists of a single, homogeneous layer of light emitting SPNs, as verified by optical, interferometric and surface probe measurements. Different batches of SPNs with different SPN diameters have been tested (69nm, 95nm, 126nm and 150 nm). All SPN-based OLEDs exhibit a light emission onset corresponding to the SPN energy gap (ca. 2.7 eV for m-LPPP, a semiconducting para-phenylene ladder polymer). The low onset is attributed to field enhanced injection of charge carriers at the aluminum cathode due to the formation of stalactite-type nanostructures. A detailed comparison of the SPN-based and bulk semiconducting polymer films reveals no differences in the basic optoelectronic properties.