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This study investigated the effect of dexamethasone (DEX) on intracellular calcium levels and the expressions of transient receptor potential cation channel subcomponent V member 6 (<i>TRPV6</i>), sodium-calcium exchanger 1 (<i>NCX1</i>), and plasma membrane calcium ATPase 1 (<i>PMCA1</i>) in A549 cells. The intracellular calcium level, by using the calcium indicator pGP-CMV-GCaMP6f, increased following DEX treatment for 6, 12, and 24 h in A549 cells. In addition, Rhod-4 assay after DEX treatment for 24 h showed that DEX increased the level of intracellular calcium. The expression of the calcium influx <i>TRPV6</i> gene significantly increased, whereas the expressions of the calcium outflow <i>NCX1</i> and <i>PMCA1</i> genes significantly decreased with DEX treatment. The mRNA levels of surfactant protein genes <i>SFTPA1</i>, <i>SFTPB</i>, <i>SFTPC</i>, and <i>SFTPD</i> and the secreted airway mucin genes <i>MUC1</i> and <i>MUC5AC</i> were investigated by treating cells with DEX. The DEX treatment decreased the mRNA levels of <i>SFTPA1</i> and <i>SFTPB</i> but increased the mRNA levels of <i>SFTPC</i> and <i>SFTPD</i>. The <i>MUC1</i> mRNA level was increased by DEX treatment, whereas <i>MUC5AC</i> mRNA was significantly decreased. These results indicate that DEX influences the intracellular calcium level through <i>TRPV6</i>, and affects pulmonary surfactant genes and secreted airway mucin genes in A549 cells.