The textbook "X-ray Crystallographic Investigation of Pyrrole Derivative" offers a comprehensive analysis of the three-dimensional structure of a novel halogen derivative of pyrrole, specifically 2-amino-1-(4-iodo-phenyl)-5-oxo-4,5-dihydro-1H-pyrrole-3-carboxylic acid ethyl ester. Pyrrole is a heterocyclic aromatic compound that plays a significant role in the fundamental metabolism of all life processes. The investigation employs X-ray diffraction techniques to systematically explore the structure-function relationships of biologically relevant heterocyclic molecules. This book is aimed at professionals and students engaged in organic chemistry, structural biology, and related disciplines.