Background: Classification of left ventricular diastolic function (LVDF) by echocardiography is controversial. The aim of this study was to evaluate the impact of the last 2016 recommendations for LVDF evaluation on brain natriuretic peptide (BNP) levels, proportion of final heart failure (HF) diagnosis, and cardiovascular outcomes. Methods: Outpatients with first consultation at a one-stop HF clinic (2009-2014) were screened. The initial visit included echocardiography with LVDF evaluation and determination of BNP level. HF diagnosis was confirmed or ruled out at the end of the visit. Cardiovascular events during follow-up were recorded. LVDF classification was originally performed with the 2009 recommendations and reevaluated using the 2016 recommendations. Results: A total of 157 patients (mean age 73.24 +/- 10.3 years; 70.1% women) were included. Originally (2009 recommendations), most of the patients were classified with grade I diastolic dysfunction (DD; 67.5%). After the reanalysis using the 2016 recommendations, 49% were reclassified with normal LVDF. These subjects showed lower BNP levels (40.8 pg/mL) and a lower proportion of HF diagnosis (9.6%). Another part of the initial grade I DD group (31.1%) was reclassified with indeterminate LVDF; they had intermediate BNP levels, proportion of HF, and rate of cardiovascular events. Lower reclassification rates were observed in the other groups of DD. Kaplan-Meier survival curves showed significantly better prognostic stratification after the reclassification (P = .539 vs P = .003). Conclusions: Current recommendations for the evaluation of LVDF by echocardiography resulted in more accurate classification of patients, according to their BNP levels, HF diagnosis, and cardiovascular outcomes, especially for those patients previously classified with grade I DD.