In this article we review the experimental observation of ferromagnetism in metal-oxide systems. This is relevant for the application of the most commonly used metal-oxide, indium tin-oxide (ITO), in organic electronic devices where organic magnetoresistance phenomenon has recently been observed. We provide experimental evidence of ferromagnetism in commercial ITO substrates and investigate the role of impurities in giving rise to such effects. Magnetoresistance have also been observed in organic diodes without any ITO contacts. However, it is important to take into account the intrinsic ferromagnetism in the ITO when interpreting the experimental data for devices with ITO. The possible limitations of using ITO are discussed in the article.