Phaeochromocytomas (PCs) are adrenal chromaffin cell tumours; paragangliomas (PGLs) are derived either from parasympathetic paraganglia of the skull base and neck (HNPGLs: glomus caroticum, jugulare, tympanicum and vagale) and anterior/middle mediastinum, or from sympathetic-associated chromaffin paraganglia in the abdomen, pelvis and (rarely) the posterior mediastinum. PCs and PGLs (collectively, PPGLs) present in myriad ways, often dependent upon their specific genetic alteration (either germline or somatic). Several diagnostic advances in PC/PGLs converge on the basic principle of a priori assessment: this presentation will use clinical cases to highlight how baseline probabilities influence choice of testing across a range of modalities– biochemical, structural, functional, histological and genetic - and how these different tests are integrated to a final diagnosis. Specific diagnostic advances highlighted will include: adjusted thresholds for fractionated metanephrines measured by LC/MS-MS, according to baseline risk of disease; utility of plasma 3-methoxytyramine for HNPGLs and/or metastatic disease; careful use of pre- and post-contrast densities on CT imaging; use of MR angiography for HNPGLs; diffusion-weighted imaging in B mode (DWI-B) in whole body MRI; MR spectroscopy to assess succinate content in PPGL; the choice of PET tracers (18F-FDG, 68Ga-DOTATATE or 18F-DOPA) depending on tumour genetics; imaging surveillance in asymptomatic mutation carriers; increased range of immunohistochemistry (SDHB, SDHA, FH, 2SC) to assist genetic interpretation; genetic testing pathways, including multipanel/exome germline sequencing or tumour-first testing; and the advent of liquid biopsies.