... We have mapped the central region of the spiral galaxy NGC 1808 in the 12CO J=1-0, J=2-1, J=3-2 lines and measured 13CO J=1-0, J=2-1, C18O J=1-0, HCN J=1-0 and an upper limit on CS J=2-1 at the central position. ... The line intensity ratios indicate that the central molecular gas of NGC 1808 is in a state of high excitation compared with giant molecular clouds in the disk of the Milky Way. ... A simple estimate of the pressure felt by these clouds leads to further constrains on their properties. ...