Ice-ice disease in cultivated algae occurs due to pathogenic bacterial infections. Generally, ice-ice disease is characterized by whitening of the branches and initiated with the color changes of the thalli becomes transparent. This study was aimed to isolate and identify bacteria on seaweed Gracilaria verrucosa infected by ice-ice. Isolated bacteria was inoculated in Tryptic Soy Agar (TSA) and Thiosulphate Citrate Bile Sucrose (TCBS). Morphological and biochemical characterization of the bacterial isolates revealed eight species of bacteria were found in infected thalli including Acinetobacter sp., Pseudomonas sp., Bacillus sp., Micrococcus sp., Corinoverm sp., Cytophaga sp., Vibrio mimicus and V. Campbelii, but not all identified bacteria are pathogens on Gracilaria verrucosa. The pathogenic bacteria were Acinetobacter sp, Pseudomonas sp, Bacillus sp, Cytophaga sp. and Vibrio sp.