Process safety management introduced a formal, structured, management systems approach to accident prevention that represented a "step change" improvement in identifying and reducing the potential for major process plant accidents. Although the process safety management elements have proven effective, the overall sustainability remains a challenge. This paper highlights the importance of a strong process safety culture that is needed to sustain a strong process safety performance. We use the Columbia Shuttle disaster incident as a backdrop to focus the attention on the significance of not having an optimal "Safety Culture." Examples have been included from our industry to further exemplify its broad applicability. The paper proposes an approach that will help organizations to self-assess the state of the process safety culture in their organizations, which can be an aid in their ongoing cultural improvement effort. Four important cultural themes are identified and described: (1) Create awareness and buy-in about process safety culture themes, (2) adapt process safety culture themes to your company experience, (3) use suggested indicators to identify specific areas of improvement, and (4) develop a strategic improvement plan to strengthen and sustain process safety culture. (c) 2005 American Institute of Chemical Engineers Process Saf Prog 25: 16-20, 2006.