Bacteriochlorins are a class of macrocycle with two reduced pyrroline rings replacing two of the pyrrole rings found in porphyrins. Bacteriochlorins occur naturally in photosynthetic pigments (bacteriochlorophylls a and b), which have been isolated from purple photosynthetic bacteria of the orders Rhodospirillales and Rhizobiales. The resulting alteration in the conjugated π electron system of the bacteriochlorin macrocycle affects their optical absorption spectrum, excited state, and redox properties. Bacteriochlorins possess large absorption peaks in the near-infrared region of the spectrum and the ability to carry out both Type II energy transfer and Type 1 electron transfer reactions depending on the coordinated central metal atom. The main disadvantage of bacteriochlorins as photosensitizers is their instability both in the dark and light. One solution to this instability was to prepare bacteriochlorins that are stabilized against adventitious oxidation by the presence of a pair of geminal dimethyl groups. This route was used to prepare a range of bacteriochlorins containing positively charged substituents that allow them to bind to and penetrate different classes of bacteria and fungi. Four compounds with two, four, or six quaternized ammonium groups, or two basic amine groups, were compared for light-mediated killing against Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli, and fungal yeast Candida albicans. All four compounds showed six logs of killing at 1 μM or less against S. aureus, and increasing cationic charge killed more E. coli. Only the compound with basic groups was highly active against C. albicans. Another set of three monosubstituted cationic bacteriochlorins were tested against a panel of pathogenic microorganisms noted for drug-resistant S. aureus, Enterococcus faecalis, E. coli, Acinetobacter baumannii, C. albicans, and Cryptococcus neoformans. All three compounds were highly effective against Gram-positive bacteria (>6 logs of eradication at ≤200 nM and 10 J/cm2). The dicationic bacteriochlorin (BC38) was best against Gram-negative bacteria (>6 logs at 1–2 μM), while the lipophilic monocationic compound was best against fungi (>6 logs at 1 μM).