This study compares Polish managers’ perceptions of their organizational culture and their beliefs concerning attributes necessary for leadership effectiveness, investigated in 1996/1997 and 2008/2009. As was unexpected, our results show that Polish managers of 2008/2009 score significantly higher than managers of 1996/1997 on Power Distance, Individualism, Masculinity and slightly lower on Future Orientation and Humane Orientation. Our findings suggest that more individualistic orientation in Polish organizations is still necessary in order to survive and be effective during the current turbulent and highly uncertain economic and business conditions. Relatively higher scores on Power Distance on the part of Polish managers being studied in the years 2008/2009 are also in line with findings concerned with attributes necessary for leadership effectiveness. Mean comparisons on beliefs concerning attributes necessary for leadership effectiveness show that Polish managers of 2008/2009 in comparison with their counterparts studied in 1996/1997 scored higher on Autocratic Orientation, Risk Avoidance, Isolationistic Orientation and Individualistic Orientation. Our findings are also consistent with regard to leadership attributes of Performance Orientation, Team Orientation, Decisiveness, Diplomatic, Humane Orientation, Integrity, Visionary and Charismatic/Inspirational, which are somewhat less strongly associated with leadership effectiveness by Polish middle managers investigated in 2008/2009 in comparison with their counterparts studied in 1996/1997.