Multiple Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) instruments can measure from the ground the absorption by nitrogen dioxide (NO<sub>2</sub>) of scattered sunlight seen in multiple viewing directions. This paper studies the potential of this technique to derive the vertical distribution of NO<sub>2</sub> in the troposphere. Such profile information is essential for detailed comparisons of MAX-DOAS retrievals with other measurement techniques for NO<sub>2</sub>, e.g. with a lidar or from space. <br><br> The retrieval algorithm used is based on a pre-calculated look-up table and assumes homogeneous mixing of aerosols and NO<sub>2</sub> in layers extending from the surface to a variable height. Two retrieval models are compared: one including and one excluding an elevated NO<sub>2</sub> layer at a fixed altitude in the free troposphere. An ensemble technique is applied to derive retrieval uncertainties. <br><br> Sensitivity studies demonstrate that NO<sub>2</sub> in the free troposphere can only be retrieved accurately if: (i) the retrieved boundary layer profiles for aerosols and NO<sub>2</sub> correspond to the real ones, (ii) if the right a-priori choice is made for the (average) height of free tropospheric NO<sub>2</sub>, and (iii) if all other error sources are very low. It is shown that retrieval models that are capable of accurate NO<sub>2</sub> retrievals in the free troposphere, i.e. models not constrained too much by a-priori assumptions, have as a major disadvantage that they will frequently find free tropospheric NO<sub>2</sub>, also when it is not present in reality. This is a consequence of the fact that NO<sub>2</sub> in the free troposphere is poorly constrained by the MAX-DOAS observations, especially for high aerosol optical thickness values in the boundary layer. Retrieval of free tropospheric NO<sub>2</sub> is therefore sensitive to a large number of error sources. For this reason it is advised to firmly constrain free tropospheric NO<sub>2</sub> in MAX-DOAS retrieval models used for applications such as satellite validation. This effectively makes free tropospheric NO<sub>2</sub> a source of error for MAX-DOAS retrieval of NO<sub>2</sub> profiles in the boundary layer. <br><br> A comparison was performed with independent data, based on MAX-DOAS observations done at the CINDI campaign, held in the Netherlands in 2009. Comparison with lidar partial tropospheric NO<sub>2</sub> columns showed a correlation of 0.78, and an average difference of 0.1× 10<sup>15</sup> molec cm<sup>−2</sup>. The diurnal evolution of the NO<sub>2</sub> volume mixing ratio measured by in-situ monitors at the surface and averaged over five days with cloud-free mornings, compares well to the MAX-DOAS retrieval: a correlation was found of 0.94, and an average difference of 0.04 ppb.