No dyspepsia-specific questionnaire currently exists in Spanish. The Spanish Language Dyspepsia Questionnaire (SLDQ) was developed based on Rome dyspepsia criteria, other questionnaires, and common symptoms. Self-reported normal and dyspeptic volunteers (N = 63) in Chiapas, Mexico, participated in a validation study. We assessed intra- and interrater reliability by test-retest studies and established validity by both correlation to the Short Form-36 (SF-36) and comparison of scores between normals and dyspeptics. The total SLDQ score showed a wide distribution (range 0-78, mean 23.7 +/- 21.9). Internal reliability of the SLDQ was high (Cronbach's a = 0.93). Intra- and interrater reliability were excellent (scores from the first and second interviews not statistically different; P = 0.94; intraclass correlation coefficient = 0.96). SLDQ scales correlated appropriately with the SF-36. The SLDQ distinguished self-classified normals from dyspeptics (P < 0.001). The SLDQ fills the unmet need for a valid, reproducible, and multidimensional Spanish-language instrument to measure dyspepsia. Additionally, we have made suggestions for the development of symptom-quantifying questionnaires.