Caenorhabditis elegans is a small, transparent nematode and a well-known model organism for different biological studies. Its short life cycle and well-defined biology make it easy to study its physiological processes and track the fate of injected samples during microinjection. Microinjection is a very powerful and versatile technique involving incorporation of oligonucleotides, chromogenic dye, or a fluorophore into the worm’s body, which can be used for genotypic and phenotypic analysis. In microinjection experiment, a very thin glass needle/micropipette is used to inject the samples into the worm’s body. It is also used as a physical method of gene transfer and is generally used in several fields like genetic engineering, molecular cell biology, in vitro fertilization, and generation of transgenic C. elegans. It can be used to label biomolecules to study its physiological function. Similarly, oligonucleotides can be injected into the worm’s gonads to generate transgenic generations using knock-in or knock-out approaches. Microinjection requires skilled personnels, preciseness, and specific volume transfer, making it a robust biological technique.