BODIPY dyes are promising candidates for photodynamic therapy (PDT) due to their high fluorescence and ability to generate singlet oxygen when modified to enhance triplet state formation. PDT involves a photosensitizer, light, and oxygen to produce reactive oxygen species that damage cells. Current PDT agents, such as porfimer sodium and 5-aminolevulinic acid (ALA), have limitations in terms of toxicity, solubility, and depth of penetration. BODIPY dyes offer advantages such as high extinction coefficients, resistance to photobleaching, and higher light-dark toxicity ratios. However, their fluorescence must be suppressed to promote triplet state formation for effective PDT. Halogenated BODIPYs, such as 2 and 3, have been shown to generate singlet oxygen efficiently, with 3 localizing in mitochondria and inducing cell cycle arrest. Other halogenated BODIPYs, like 18 and 19, exhibit high singlet oxygen generation quantum yields and are effective in PDT. Aza-BODIPYs, such as 18, have shown promising PDT activity with high singlet oxygen generation and minimal skin photosensitivity. These compounds also exhibit good photostability and can be used for both imaging and PDT. BODIPY dyes with modified substituents, such as those with electron-withdrawing groups, can enhance singlet oxygen generation and reduce fluorescence. The use of photoinduced electron transfer (PET) can further modulate singlet oxygen generation, allowing for targeted PDT. Additionally, BODIPY dyes can be used as sensors for reactive oxygen species, providing insights into PDT mechanisms. Future research should focus on developing clinically useful PDT agents with improved targeting and reduced toxicity. BODIPY-based agents, particularly aza-BODIPYs, show promise for clinical development due to their favorable properties. The integration of BODIPYs with targeting ligands for cell-surface receptors overexpressed in tumors could enhance their therapeutic potential. Overall, BODIPY dyes represent a promising class of photosensitizers for PDT, with ongoing research aimed at optimizing their properties for clinical applications.BODIPY dyes are promising candidates for photodynamic therapy (PDT) due to their high fluorescence and ability to generate singlet oxygen when modified to enhance triplet state formation. PDT involves a photosensitizer, light, and oxygen to produce reactive oxygen species that damage cells. Current PDT agents, such as porfimer sodium and 5-aminolevulinic acid (ALA), have limitations in terms of toxicity, solubility, and depth of penetration. BODIPY dyes offer advantages such as high extinction coefficients, resistance to photobleaching, and higher light-dark toxicity ratios. However, their fluorescence must be suppressed to promote triplet state formation for effective PDT. Halogenated BODIPYs, such as 2 and 3, have been shown to generate singlet oxygen efficiently, with 3 localizing in mitochondria and inducing cell cycle arrest. Other halogenated BODIPYs, like 18 and 19, exhibit high singlet oxygen generation quantum yields and are effective in PDT. Aza-BODIPYs, such as 18, have shown promising PDT activity with high singlet oxygen generation and minimal skin photosensitivity. These compounds also exhibit good photostability and can be used for both imaging and PDT. BODIPY dyes with modified substituents, such as those with electron-withdrawing groups, can enhance singlet oxygen generation and reduce fluorescence. The use of photoinduced electron transfer (PET) can further modulate singlet oxygen generation, allowing for targeted PDT. Additionally, BODIPY dyes can be used as sensors for reactive oxygen species, providing insights into PDT mechanisms. Future research should focus on developing clinically useful PDT agents with improved targeting and reduced toxicity. BODIPY-based agents, particularly aza-BODIPYs, show promise for clinical development due to their favorable properties. The integration of BODIPYs with targeting ligands for cell-surface receptors overexpressed in tumors could enhance their therapeutic potential. Overall, BODIPY dyes represent a promising class of photosensitizers for PDT, with ongoing research aimed at optimizing their properties for clinical applications.