A large body of literature showed the importance of dietary patterns (DPs) analysis in nutritional epidemiology. The objective of this research was to derive and characterize adults dietary patterns in a large Italian population-based cohort and to assess individuals’ diet adherence with z-scores. Participants to the third Italian National Food Consumption Survey (INRAN-SCAI 2005-06) were included. We classified all food items (N = 878) into 24 pre-defined food groups according to a modified version of the updated food classification system FoodEx2. Dietary patterns were obtained through principal component analysis, after adjusting log-transformed input variables, without minimum values, using the residual method. Relying on data from 2831 subjects (median age 47, IQR 35-60), five principal components (PC) were retained, explaining 35.63% of the overall variance. PC1 was similar to the high-fat diet characterized by positive loadings for vegetables, starchy roots, eggs products, fat and oils, and low amount of alcoholic beverages. PC2 was a picture of a carnivorous eating behavior, positively charged by processed meat, offals, other meats, juices, special nutritional, composite food, and snacks. PC3 was representative of a health conscious, positively loaded by vegetables, fruits and water, negatively associated with the consumption of pork meat and alcoholic beverages. PC4 showed similarities with a vegetarian diet, positively loaded by grain products, vegetables, herbs, and spices. The last PC represents an unhealthy dietary pattern, positively charged by sugar and confectionery, non-alcoholic beverages and negatively correlated with vegetable consumption. According to z-scores, 69% of our cohort showed high DPs adherence. These findings are valuable for understanding the dietary habits of adults in Italy, to orient public health policies and promote healthier food behaviors in the future.