The sodium channel Na_v1.7 is preferentially expressed in nociceptive neurons and is believed to play a crucial role in pain sensation. Four alternative splice variants are expressed in human dorsal root ganglion neurons, two of which differ in exon 5 by two amino acids in the S3 segment of domain I (exon 5A and 5N). Two others differ in exon 11 by the presence (11L) or absence (11S) of an 11-amino-acid sequence in the loop between domains I and II, an important region for PKA regulation. In the present study, we used the whole-cell configuration of the patch clamp technique to investigate the biophysical properties and 8Br-cAMP modulation of these splice variants expressed in tsA201 cells in the presence of the 1-subunit. The alternative splicing of Na_v1.7 had no affect on most of the biophysical properties of this channel, including activation, inactivation, and recovery from inactivation. However, development of inactivation experiments revealed that the isoform containing exon 5A had slower kinetics of inactivation for negative potentials than variant containing exon 5N. This difference was associated with higher ramp current amplitudes for isoforms containing exon 5A. Moreover, 8Br-cAMP-mediated phosphorylation induced a negative shift of the activation curve of variants containing exon 11S while inactivation properties were unchanged. Isoforms with exon 11L were not modulated by 8Br-cAMP-induced phosphorylation. We conclude that alternative splicing of human Na_v1.7 can specifically modulate the biophysical properties and cAMP-mediated regulation of this channel. Changing the proportions of these variants may thus influence neuronal excitability and pain sensation.