High fluorescence quantum yields, high singlet oxygen quantum yields and intense absorptions in the phototherapeutic window are fundamental properties for compounds intended for fluorescence diagnosis and photodynamic therapy. We report on photostable chlorins that combine these properties. The fluorinated tetraphenylchlorin FCMet has ΦF = 0.396 and ΦΔ = 0.58 ± 0.07, whereas F2CMet has ΦF = 0.360 and ΦΔ = 0.54 ± 0.05, and both have molar absorption coefficients larger than 30,000 M(-1) cm(-1) above 650 nm. These dual functional agents use nearly all the energy absorbed to perform the desired functions and are appropriate for theranostics applications.