Background In ~25% of echo studies discrepant diastolic measurements make the assessment of diastolic function indeterminate. We aimed to assess whether left atrial function may contribute to LV filling evaluation in patients with indeterminate diastolic function (IndtDFx). Methods In our retrospective echocardiography database we found 1674 consecutive patients in sinus rhythm, and EF≥45%. Patients were divided according to the parameters mitral E’, mitral E/E’ ratio , left atrial maximal volume index , and pulmonary pressure. Normal diastolic function (NDFx) was defined as less than 2 abnormal parameters, definite diastolic dysfunction (DDFx) as more than 2 abnormal parameters, and IndtDFx as 2 abnormal parameters. We retrospectively and randomly selected 30 patients from each group for left atrial assessment by speckle tracking echocardiography for off line strain and volumes analysis. Results: sixty seven patients were included in strain analysis. The DDFx group (n=21) and IndtDFx (n=19) were significantly different form NDFx (27) in demographics, cardiovascular risk factors., presentation and echocardiographic parameters. Phasic LA maximal and minimal volume indexes were larger in DDFx and indtDFx groups, and overall and passive LA strains were decreased in DDFx and indtDFx groups compared with NDFx group, while active strain remained in the normal range. Phasic LA minimal volume index was found to be associated with HF symptoms. Conclusion LA phasic function suggests that IndtDFx is similar to DDFx , helping in re- classification of patients with IndtDFx as DDFx. LA minimal volume index correlated with symptoms.