Endocytosis is a process that is essential to the life of all eukaryotic cells. Laboratory strains of Dictyostelium are extremely efficient in the uptake of both particles and fluid. Many different cellular processes feed into the endocytic pathway, and many organelle-associated and cytoplasmic proteins, including the ones from the cytoskeleton, contribute to the efficiency of transit. Therefore mutants, especially in genes of unknown function, must be characterized regarding their endocytic performance. We describe the most common tools and protocols to visualize and quantify all of the individual steps in endocytic transit.