Epidermal growth factor receptor tyrosine kinase inhibitors therapy, such as gefitinib, have proven to be effective for lung adenocarcinoma with epidermal growth factor receptor-sensitive mutations. However, drug resistance remains inevitable and the underlying mechanisms are still elusive and poorly understood. In order to explore the mechanisms underlying tyrosine kinase inhibitors resistance, we used long non-coding RNA microarray analysis and found that long non-coding RNA H19 was highly expressed in gefitinib-resistant cell lines. In addition, knockdown of long non-coding RNA H19 was found to be able to decrease cell proliferation, half maximal inhibitory concentration (IC50) of gefitinib, migration and invasion. Mechanistically, we demonstrated that long non-coding RNA H19 positively regulated dimethylarginine dimethylaminohydrolase-1 expression via sponging miR-148b-3p. Furthermore, overexpression or inactivation of miR-148b-3p could enhance or reverse the inhibitory effect of long non-coding RNA H19 inhibition in lung adenocarcinoma cells, respectively. High expression of either long non-coding RNA H19 or dimethylarginine dimethylaminohydrolase-1 was associated with poorer overall survival in patients with lung adenocarcinoma, while high expression of miR-148b was associated with better overall survival. Overall, our data revealed that long non-coding RNA H19 confers resistance to gefitinib via miR-148b/dimethylarginine dimethylaminohydrolase-1 axis in lung adenocarcinoma, which offers a new insight into the epidermal growth factor receptor tyrosine kinase inhibitors therapy resistance.