Detection of the test agrochemical and determination of the chemical identity of its metabolites and other breakdown products in plant, soil, and water are carried out after extraction from the test sample. The extracted radiolabeled agrochemical and its metabolites are normally identified by comparing their chromatographic properties with authentic reference standards. The identities of some metabolites are determined or confirmed using spectroscopic methods, such as mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. This chapter discusses the spectroscopic analysis of radiolabeled samples isolated from agrochemical metabolism and degradation studies. The role of various physicochemical factors that affect extraction and purification of the target analytes for spectroscopic analysis is also explained. The steps involved in the mass spectrometric analysis and the underlying principles of sample ionization in EI, CI, APCI, and ESI modes are discussed. Features of mass spectra and total ion chromatograms of radiolabeled compounds are explained, and examples of isotope patterns and ion cluster analysis are presented. The importance of mass fragmentation and advantages of high-resolution mass spectrometry in structure elucidation process are discussed. The NMR spectroscopic techniques used in the identification of agrochemical metabolites and their conjugated endogenous moieties are also presented.