Immunofluorescent (IF) microscopy is a powerful tool used in cellular and molecular biology to monitor the subcellular localisation of proteins. By combining the advantages of immunostaining and confocal light microscope, IF microscopy can be used to assess the colocalization of two or more proteins within the cell. Here, we describe a method that can be used to verify the correct localisation of HA-tagged Golgi proteins (like TMEM115-3HA, or GolgiTAG), by assessing their colocalisation with known Golgi markers such as GM130, GOLGIN97 and ACBD3. Furthermore, this method can be used to investigate whether HA-tagged, non-Golgi annotated proteins transiently expressed in cells localise at the Golgi, by assessing their colocalisation with ACBD3.