This observational study evaluated the treatment outcomes of clinical factors on the patients with lung adenocarcinoma with epidermal growth factor receptor mutations who received tyrosine kinase inhibitors as first-line treatment.Patients with stage IIIb or IV lung adenocarcinoma with mutated epidermal growth factor receptor were enrolled retrospectively between March 2010 and December 2017. The hematologic markers on progression-free survival (PFS) and overall survival (OS) were analyzed.Totally 190 patients were enrolled. In univariate analysis by hematologic markers, lower lymphocyte percentage and higher platelet count were associated with significantly poor PFS and OS. Multivariate analysis showed lower lymphocyte percentage was independent poor prognostic factors for PFS and OS. Higher platelet count was an independent poor prognostic factor for OS only.Patients with lung adenocarcinoma receiving tyrosine kinase inhibitors with lower lymphocyte percentage and higher platelet count had poorer prognoses compared with other patients.