PhiKZ is a bacteriophage that infects Pseudomonas aeruginosa, an opportunistic human pathogen. The phage phiKZ is known for its large genome and complex structure, making it a notable subject for structural biology studies. Among all its parts, the baseplate is the most complex. It adheres to the phage prey and triggers the genome ejection. The signal that triggers the ejection travels from the tail fibres to the tail through the baseplate. Here, we used cryo-Electron Microscopy to visualise the structure of the phiKZ tail and the baseplate at high resolution, the first one of a jumbo bacteriophage. Our results reveal an intricate network of proteins organised in six-fold symmetry. Structural comparisons with related systems highlight the universal conservation observed in contractile injection systems. This sheds light on phiKZ’s baseplate specificities and suggests a potential mode of action. Its structural analysis enhances our understanding of phiKZ and contributes with valuable knowledge to the broader field of myovirus biology.