Introduction: There is word finding problems among children with language and learning disorders. One of the most popular evaluation ways for word finding is formal assessment. The test of word finding- second edition is a most reliable one. In this study, validity and reliability of this test is determined in Isfahanian 8-11 year- old students. Method: This is a transactional- descriptive survey. After translation and change, the test of word finding randomly administered in 210 children 8-11 year- old. Parent’s permission was taken, too. Test’s items were analyzed by using Item-Response Theory and entering responses’ pattern in form of numbers (zero and one) in Bilog-MG(6) software. Then, reliability was achieved by using Cronbach’s coefficient alpha and statistical indexes of intermediate form were calculated by using SPSS (13) software. Results: The mean of word finding scores in 3 age group (8, 9, 10, 11 years) were 40.30, 45.51, 48.05 and 45.11 respectively. It shows that when the children become older, the mean of scores increase gradually (Pvalue: 0.00, α: 0.05). Also the reliability of test was 0.84. Conclusion: The discrimination power of items in Persian students is equal to the discrimination power of German's test. It shows that this test has a good potential to differentiate between students with various word finding abilities. Reliability of this test is good based on psychometric indexes. Therefore, a valid and reliable test to evaluate word finding of Persian children is produced. Key words: word finding, the test of word finding (second edition), reliability, validity.