This paper describes an evaluation methodology for assessing the decision impact of the intelligent Mobile Decision Support Triage prototype called "iTriage", which was implemented on a handheld personal digital assistant (PDA). The initial evaluation of iTriage by a clinician has provided validation of the proposed model in terms of its capability to for decision support. Since then the recommended changes have been made to iTriage for further testing. The described research evaluates the prototype using lab experiment study design involving nursing students as participants. The study measures the decision impact of iTriage on triage decision making process and outcomes. The paper describes the resulting findings from the data collected and comments on the use and applicability of the mobile DSS prototype for medical triage.