Carbon nanotubes (CNT) and their mechanical properties have been investigated since the early 1990s. The main research was focused on using of CNTs to reinforce polymer and ceramic matrices but the interest in metallic-CNT composites has grown considerably in the last decade. Of particular interest is CNT-reinforced aluminium alloys which have promising potential for application in many industrial sectors such as aerospace, automotive and electronics. Composites were made by adding CNT’s to molten aluminium alloy via gravity casting into a mould. Ten nanocomposite billets were prepared using this technology: two billets of pure aluminium alloy LM24 and two billets of the same alloy with different CNT volume content of 0.1, 0.3, 0.5 and 1.0%. Then two types of specimens: beams with the dimensions of 80mm or 70mm or 60mm x 10mm x 2mm and plates with the dimensions 80mm x 60mm x 2mm were machined from these billets for experimental investigations. It is necessary to note that specimens were taken from 5 different positions from a large billet to study a variation of material properties as a function of billet thickness. Different nondestructive techniques for the elastic and dissipative material property characterisation were developed and adapted for the testing of nanocomposite specimens with small geometrical dimensions. Static approach using a three-point-bending test and two dynamic methods, namely, impulse excitation method and inverse technique based on vibration tests and using the planning of experiments and response surface methodology were applied for the determination of the elastic properties of these materials. The dissipative material properties were characterised by a structural loss factor obtained by the peak-picking method analysing the frequency response functions of specimens in the points of resonance. The addition of CNT to the aluminium alloys did not yield a visible increase in their elastic properties. However, instability in elastic properties through the thickness of billet was observed. This could be explained by a gradient of CNTs distribution due to the limitations of the gravity casting process. The experimental results show that addition of CNTs to this aluminium alloy decreases their dissipative material properties for bending and twisting modes. If for bending modes the maximal average deviation (in comparison with pure aluminium alloy) is 32%, for twisting modes the maximum average deviation was 45%. It is necessary to note that material investigated did contain pores. Unfortunately, pores have considerable influence on the dissipative material properties therefore it was not possible to obtain a clear dependence of the material loss factors on frequency for the specimens with different CNT volume content in a wide frequency range. The problem of a gradient of CNT distribution throughout the aluminium alloy and porosity of material could be probably overcome producing CNT-reinforced aluminium alloys using die casting.