The thermal comfort of inhabitants of urban areas is strongly impacted by urban heat islands (UHI). This discomfort is strengthened with the heat waves produced by the global warming. Cities therefore are looking for solutions to improve the thermal comfort. The integration of vegetation in sustainable urban planning projects seems to be a good lever of action. Through different mechanisms, the vegetation, which can be found in different forms as lawn, isolated trees, parks, green roofs and green facades can contribute to the attenuation of the UHI. Trees contributions might be highly significant because trees produce a high quantity of latent heat fluxes and allow to cool large surfaces thanks to their shadow. In order to be able to predict the vegetation impact on microclimate, according to its location in urban areas of different typologies, numerical simulations of the interactions between vegetation and urban environment are carried out. The LASER/F model (Latent Sensible Radiation Fluxes), developed by the ICube laboratory, is a numerical model designed to simulate the urban microclimate mainly at the district and street scale (Kastendeuch et al., 2017). Usually, numerical models at this scale take into account the vegetation with simple geometries. The aim of our study is to integrate the lawn and trees with complex geometries into the LASER/F model and to validate this integration with field measurements in order to study the impact of this kind of vegetation on urban microclimate. The case study is a 20,000 square meters garden located in Strasbourg, France. The microclimate in this green park is simulated for four hot sunny days during the summer 2014. Firstly, the functioning of the implemented vegetation module is presented. Then, several model simulations are compared to corresponding field measurements. This comparison is made for three elements: i) lawn and soil; ii) trees and their crowns; and iii) the whole park. Thanks to the diversity of field measurements, it is possible to base the comparison on many variables, such as surface temperature, radiative and heat fluxes, and even the thermal comfort index. The analysis of the results shows that the LASER/F microclimatic model is very satisfying since it correctly estimates the interactions between the vegetation and the urban environment of the park. Once the validation phase has been achieved, the model can be used to study the impact of the vegetation on the creation of urban microclimates. For this purpose, different scenarios with more or less vegetation and more or less mineral surfaces are tested. Also the effect of tree’s positions is analyzed. This innovative study confirms the potential of microclimate models to support decision makers in introducing in an adequate way vegetation in their urban planning projects.