G1 (1-[5-bromofur-2-il]-2-bromo-2-nitroethene) is a novel antimicrobial compound developed in Cuba with reported broad-spectrum activity against Gram-positive and -negative bacteria, yeasts and fungi. A compound of this nature may have considerable therapeutic potential. We tested the in vitro activity of this novel compound against 3595 organisms using microbroth dilution. The following are MIC 5 0 , MIC 9 0 and range respectively for some of the microorganisms tested: E. coli 16, 16, 4-32; Klebsiella sp. 16, 16, 8-32; Citrobacter sp. 16, 16, 8-16; Enterobacter sp. 16, 16, 8-16; Proteus sp. 16, 16, 8-16; Coagulase-negative staphylococci 16, 32, 4-32; Enterococcus sp. 16, 32, 2-32; Staphylococcus aureus 8, 16, 4-16; Streptococcus agalactiae 4, 8, 4-8; Streptococcus pyogenes 4, 8, 0.25-16; Candida albicans 2, 2, 1-4; Candida tropicalis 4, 4, 2-4; Candida sp. 2,4, 1-4. MIC values appear lower for Gram-positive microorganisms and yeasts. G1 appears to be a novel antimicrobial agent with broad spectrum activity against bacterial and fungal pathogens. Defining the activity of this compound against multi-resistant bacteria is a priority.