Organizational culture has been shown by organizational psychology to influence important aspects of staff behaviour. In particular, mismatches between staff perceptions of real and ideal organizational cultures have been shown to be associated with a range of negative outcomes for staff, such as stress, sickness and staff turnover. The present study investigates organizational culture in services for people with intellectual disabilities. The aim was to discover the prevalent organizational cultures in these services, and associations between organizational culture and staff outcomes. As part of a large-scale survey of staff in services for people with intellectual disabilities, information concerning organizational culture and staff outcomes was collected from 450 staff. A self-report measure of real and ideal organizational culture produced nine dimensions of organizational culture: (I) tolerant/staff-oriented; (2) achievement-oriented; (3) innovative; (4) analytical; (5) social relationships; (6) rewarding staff; (7) stable work environment; (8) demanding; and (9) conflict management. These nine dimensions of organizational culture showed generally adequate psychometric properties. While there was some variation in organizational culture across services, there is little variation across staff with different job titles. Overall, the staff rated real organizational cultures to be relatively high in achievement orientation and fostering social relationships, and relatively low in managing conflict and providing rewards for staff. Staff rated ideal organizational cultures to be high in rewarding staff, being tolerant/staff-oriented and fostering social relationships, and low in demands on staff. Except for the dimension of making demands on staff, where staff rated organizations as considerably higher than ideal, staff generally rated organizations as being less than ideal on all dimensions of organizational culture. Organizational psychology theory predicts that poor 'person-organization fit' (i.e. a greater mismatch between real and ideal organizational culture) will be associated with a range of negative staff outcomes. This theory was largely supported by findings of the present study. The implications for practice and for future research are discussed.