Screening for early signs of Autism Spectrum Disorder is essential for referral to early intervention. Given the lack of instruments for this purpose in Brazil, the Questionnaire for Screening Early Signs of Autism Spectrum Disorder (QR-TEA) was developed. A preliminary study indicated validity evidence based on content. Understanding the validation of an instrument as a continuous and uninterrupted process, this thesis aimed to analyze validity evidence based on internal structure and evidence of validity based on relationships with external measures. The results indicate plausibility of a factorial solution of two factors (χ² / gl = 1; RMSEA = 0.00, 90% CI = 0,00-0,06; CFI = 1.03; TLI = 1.03) and also of a general factor (χ² / gl = 1.49; RMSEA = 0.06, 90% CI = 0.05-0.06; CFI = 0.95; TLI = 0.95). In the two-factor model, the reliability was adequate (above 0.70) for both factors and the measure of replicability of the factor structure suggested that the two factors could be replicable in future studies (H>0.80). The internal consistency of the instrument assessed by Cronbach s alpha was also high (0,80). The results also indicate that QR-TEA has a strong, positive and significant correlation with the instruments CARS (ρ = 0.890; p <0.001), M-CHAT (ρ = 0.890; p <0.001) and SRS- 2 (ρ = 0.874; p <0.001, and also with the SRS-2 scales: Communication and Social Interaction (ρ = 0.769; p <0.001) and Restricted and Repetitive Patterns (ρ = 0.751; p <0.001). Further studies are recommended to seek new verification evidence and analyze other psychometric properties of the QR-TEA.