Determining the optimal span of control for managers in healthcare has challenged administrators. Span of control can affect the outcomes of defined operational objectives. While the division of work is not a new concept, studies aimed at understanding how specific factors impact the effectiveness of a span of control is limited within the healthcare literature. This study found no optimal span of control for nurse managers and regression studies did not result in any clear model of factors that could best predict an optimal span. However, some factors were perceived as having more impact than others, including hours of work, unit complexity and attention to risk and quality. The results of some analysis including the impact of volume of staff failed to reject the null hypothesis. Additional work is needed on the factors that cause a perception of ineffectiveness including the effect of support help.