Introduction: Non-carious lesions are an oral health pro-blem in adults, consequently it is necessary to create mechanisms for their diagnosis and prevention. Objective: To determine the frequency of erosion, abrasion and related factors in patients treated at a university dental clinic. Material and Methods: A cross-sectional study was conducted in a sample of 153 adults treated at a university clinic in Lima, Peru, in 2018. Personal aspects (age, sex, characteristics of saliva), dietary factors, health condition, oral habits, and tooth brushing were identified. The presence of abrasion was determined according to clinical criteria through direct observation. Erosion was identified using the Basic Erosive Wear index. Generalized linear models with Poisson distribution with robust variances were used. Results: The frequency of dental abrasion (70.6%) is higher than erosion (26.1%). The presence of erosion is associated with asthma (PR= 2.11), abrasion is related to age and poor dental hygiene habits (PR= 1.67 and 1.30, respectively). Conclusion: The presence of dental abrasion is greater than dental erosion. Age and poor dental habits are factors associated with tooth abrasion. The characteristics of saliva regarding pH and salivary flow were within normal p-values.