<p>The objective was to compare in construct validity and reliability the Life Orientation Test-Revised (LOT-R) and the Brief Interactive Optimism Scale-Garcia (BIOS-G). It was used a convenience sample (1 712 Spanish-speaking people; 629 men, 1083 women). Although LOT-R presents appropriate goodness of fit in two countries, BIOS-G beats it. BIOS-G gets good <em>ω </em>values in the seven countries, and LOT-R in two only. BIOS-G shows better factor invariance. BIOS-G obtains acceptable and excellent values in <em>H</em> coefficient in the seven countries, but LOT-R in four only. Correlation between BIOS-G and LOT-R is significant, <em>r</em> = .45, p &lt;.01, (CI 95%, .41, .49). Conclusion: BIOS-G it is a good option to measure optimism.</p>
<p>Keywords: optimism, construct validity, reliability, cross-cultural comparison, Spanish speaking countries</p>