By means of HPLC-MS, metabolites of azadirachtin A, azadirachtin and other limonoids could be identified. A susbtance of molecular weight 678 was characterised as a metabolite supposed to be relevant during the degradation (deacetylation at C3) of azadirachtin A in soil. It is assigned to 3-deacetyl-azadirachtin A. This metabolite is termed azadirachtin H* since it coelutes with azadirachtin under the HPLC-conditions used. Azadirachtin H* is assumed to further degrade by the cleavage of a fragment or fragments correspong to tigloylic acid, resulting in the formation of the minor metabolit AzX with the molecular weight of 578. As another degradation product of azadirachtin A of minor quantity 3-deacetyl-azadirachtinin was suggested, which was formed from azadirachtinin, an isomerisation product of azadirachtin A. Based on the HPLC-MS results, for azadirachtin, the same degradation pattern can be assumed resulting in the formation of the minor metabolite 3-deacetyl-azadirachin (AzI*). Since azadirachtin B is lacking an acetyl-group this way of degradation is not relevant for this compound of NeemAzal. Several intermediates of the degradation of azadirachtins in soil have been detected by comparison of HPLC and HPLC-MS results. The results indicate that deacetylisation and cleavage of tigloylic acid belong to the first important degradation steps. By means of HPLC-MS, one metabolite could be characterised in considerable amounts during the degradation of azadirachtin A in soil. It is assigned to 3-deacetyl-azadirachtin A. However, it was not possible to speficy any major metabolite, since degradation products could not be clearly quantified and mass balances could not be generated. For all azadirachtins considered, 90% degradation is reached after maximally 33 days after application. This study therefore is no common route of degradation study, but nevertheless suitable for the identification of metabolites. Because radioactive labelling of azadirachtin shall be excluded, determination of bound residues is not possible. In regard to mineralisation capturing of volatiles would have been helpful. As there is no such study, it can only be concluded that 3-deacetyl-azadirachtin A is a metabolite of azadirachtin A.