The Automatic Thoughts Questionnaire (ATQ) is a widely used, 30-item, 5-point Likert-type scale that measures the frequency of negative automatic thoughts as experienced by individuals suffering from depression. However, there is some controversy about the factor structure of the ATQ, and its application can be too time-consuming for survey research. Accordingly, an abbreviated, 8-item version of the ATQ has been proposed. The aim of this study was to analyze the validity evidence of the Spanish version of the ATQ-8 in Colombia. The ATQ-8 was administered to a total of 1587 participants, including a sample of undergraduates, one of general population, and a clinical sample. The internal consistency across the different samples was good (α = .89). The one-factor model found in the original scale showed a good fit to the data (RMSEA = .083, 90% CI [.074, .092]; CFI = .96; NNFI = .95). The clinical sample’s mean score on the ATQ-8 was significantly higher than the scores of the nonclinical samples. The ATQ-8 was sensitive to the effects of a 1-session acceptance and commitment therapy focused on disrupting negative repetitive thinking. ATQ-8 scores were significantly related to dysfunctional schemas, emotional symptoms, mindfulness, experiential avoidance, satisfaction with life, and dysfunctional attitudes. In conclusion, the Spanish version of the ATQ-8 showed good psychometric properties in Colombia.