Immunochemistry specifically detects or visualizes biologically important analytes, such as disease biomarkers or pathogens, employing various detection techniques. This can be done by employing label-based assays for indirect detection of the analytes. The labels for immunochemical methods, typically with luminescence or enzymatic properties, are selected to allow a simple and fast detection, high accuracy, and reproducibility of the measurements. In this chapter, immunochemical methodology based on laser-induced breakdown spectroscopy (LIBS) detection is mainly discussed in comparison with other commonly used techniques based on luminescence or color change monitoring. Being a multielemental analytical technique, LIBS allows for the differentiation of the labels based on their elemental composition with no need for specific label properties (e.g., luminescence) while maintaining the information on the distribution of other valuable constituents. For the sake of complementarity, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) as a detection technique for immunochemical methods is also included in the chapter as it serves not only as a reference for the tag-LIBS technique. With the continual advancement of the instrumentation of both techniques, the possibility of a tandem analysis by tag-LIBS and LA-ICP-MS might be explored in the future.