The Hartwick–Solow rule for sustainability requires that depletion of natural capital be offset by a compensating increase in other forms of capital capable of generating as much income as the natural capital they replace. Many countries have not been successful in transforming natural capital into other forms of wealth. This paper investigates the process of wealth transformation for Botswana, one of the most successful resource-rich countries. Using an expanded measure of wealth that includes manufactured capital, natural capital and net foreign financial assets, Botswana's per capita wealth has increased over the past 20 years. Government has recovered and reinvested rent. However, examination of the public sector capital budget reveals considerable unproductive investment. While correction for unproductive investments still indicates sustainable development, results suggest that aggregate indicators such as national wealth or genuine savings may be misleading without further attention to the process by which natural capital is transformed into other forms of wealth.