The high resolution absorption spectrum of monodeuterated water, HDO, has been recorded by Intracavity Laser Absorption Spectroscopy (ICLAS) in the 13020-14115 cm-1 region dominated by the 4 3 band. The achieved noise equivalent absorption ( min~ 10-9 cm-1) allowed detecting transitions with line strengths as small as 2×10-27 cm/molecule which is about 10 times lower than the smallest line intensities previously detected in the region.