Cooperatives have proven to be ideal instruments for economic and social development therefore co-operation and collaboration and promotion of strategic alliances with private sector-based institutions is a crucial strategy for growth of cooperatives especially in the face of global trends. Such a structure might have far-reaching ramifications on performance evaluation and the governance structure of SACCOs'. Not to mention that as development finance institutions, SACCOs operate mostly where there is market failure due to high risk or costs (Aziakpono, 2013). Managers have to put in an effort to compete favorably. However, it beats logic to continuously source funds from members yet the contributions could be made strategically and used in investments that give members returns as dividends and relief in contributions. The objective was to examine the effect of investment on the sustainability of SACCOs in Kenya. Survey research design on 175 SACCOs, was done with reference to Nairobi County. The findings showed that investment strategies and innovation had a significant positive effect on the sustainability of SACCOs in Kenya.