Important audit judgments concerning client selection, audit program planning, and risk assessment all may be impacted by the approach taken to assess risk and to interpret audit evidence. This experimental study examines whether auditors' risk assessments are influenced by the risk assessment approach and by assertion framing. Risk assessment approach was manipulated by eliciting belief-based versus probability-based risk assessments. Assertion framing was manipulated by stating the financial statement assertions to be examined in a positive versus negative form. Four measures of risk of material misstatement are compared, including one based on the Cobb and Shenoy (2003a, 2003b, 2006) transformation of beliefs into "probabilities." Both risk assessment approach and assertion framing effects on the auditors' risk assessments are observed. Given these significant differences, the risk measure(s) the auditor chooses to focus on and the way assertions are framed are shown to be important audit choices in that such choices may impact both audit effectiveness and efficiency.