The solar photovoltaic power industry emerged in 1970 in response to the growing need for electricity generated from renewable and non-polluting sources. More than 76% of solar photovoltaic companies operating in 2010 were at risk of ceasing operations and negatively impacting the earth's ecosystems because their management practices did not address either the ecological paradox or the strategic threats facing the industry. Drucker's theory of the business, which was expanded to include stakeholders, was used in this qualitative study to explore and describe the sustainability-based best practices of two leading companies in the industry, United Power and SolarWorld. Data were collected through examination of third party verified documents and key informant interviews; these data were analyzed in a cross-case comparison. Each company has adopted management practices that address the strategic threats facing the industry. These practices included (a) creating a positive, caring, and responsive work environment; (b) implementing community-service and customer-service programs; (c) measuring and reporting ecological, social, and economic performance; (d) implementing integrated risk management; (e) supporting product and process innovation; (f) optimizing distribution networks and systems; and (g) adopting multi-faceted mission statements. The management practices of both companies support social and economic sustainability; however, these practices do not support ecological sustainability because they focus on using resources efficiently instead of restoring and enhancing the natural environment. Future research recommendations include exploring the elements of organizational culture, including values and beliefs that affect the sustainability management practices of the leading solar photovoltaic power companies.