Cellular fate is regulated by intricate signal transduction mediated by posttranslational protein modifications like phosphorylation to transmit information. As other cancer types, lymphomas frequently show dysregulation of signaling pathways that contribute to malignant transformation and tumor progression. For example, in diffuse large B-cell lymphoma the B-cell antigen receptor was identified as an oncogenic driver mediating cellular growth and survival signals. Thus, the elucidation of these complex signaling networks is crucial to gain insight into the mechanisms underlying tumorigenesis and to identify target proteins for innovative therapeutic approaches. Here, we describe a mass spectrometry-based phosphoproteomic approach for the global analysis of intracellular signaling events and their dynamics. The workflow combines phosphopeptide enrichment and fractionation with liquid chromatography-coupled mass spectrometry for the amino acid site-specific identification and quantification of thousands of phosphorylation events. Such global signaling analyses have great potential for the elucidation of oncogenic pathomechanisms, diagnostic biomarkers, and drug targets.