Colloidal nanoparticles have found numerous applications in different fields and in particular in medicine [1]. Lasers are commonly used to produce these nanoparticles, but can be also considered as powerful tools of size and shape tailoring through laser-induced fragmentation. In this area, many promising experiments have already demonstrated tremendous laser capacities [2,3]. In addition, laser interactions with nanoparticles in a confined environment are considered to have possible applications for energy production. The corresponding experiments are underway. To better control over the laser-induced fragmentation, it is important to better understand the mechanisms involved in nanoparticle heating and fragmentation in the presence of a liquid. For this, numerical modeling is performed based on a combination of different approaches. First, we use the discrete dipole approximation method to calculate absorption of nanoparticle ensemble. Then, we apply two-temperature model to study particle heating, together with the third equation for the environment. The performed analysis allows us to predict optimum laser parameters for nanoparticle size manipulation, but also to recommend nanoparticle sizes and density for the enhanced absorption, which is particularly interesting for the development of novel energy sources. [1] R. R. Letfullin, Ch. Joenathan, T. F George, and V. P Zharov Laser-induced explosion of gold nanoparticles: potential role for nanophotothermolysis of cancer, Nanomedecine, vol. 1, No. 4, pp 473-480 (2006) [2] S. Hashimoto, D.Werner and T. Uwada : Studies on the Interaction of Pulsed Lasers with Plasmonic Gold Nanoparticles toward Light Manipulation, Heat Management, and Nanofabrication, Journal of Photochemistry and Photobiology C: Photochemistry Reviews, vol.13, No.1, pp.28-54, (2012). [3] P. Blandin et al., Femtosecond laser fragmentation from water-dispersed microcolloids : toward fast controllable growth of ultrapure Si-based nanomaterials for biological applications’, J. Mater. Chem. B. vol. 1, pp 2489-2495, (2013)