The present study investigate whether diode laser activation of two nanoparticle herbal irrigants affect Enterococcus faecalis (E.faecalis) biofilm and Candida albicans (C. albicans) compared with photodynamic therapy (PDT) utilizing methelyene blue as photosensitizer (PS). Material and methods: sixty single rooted teeth had undergo mechanical preparation. Teeth were divided into 3 groups (20 teeth each), G1 : 20 teeth inoculated with Enterococcus faecalis half (n= 10) irrigated with nanocurcumin and the other half irrigated with nanoneem both activated by diode laser, G2: 20 teeth inoculated with Candida albicans irrigated similar to group 1 and G3: 10 teeth inoculated with E.faecalis and 10 with Candida albicans undergo PDT using methylene blue as PS. Results: For E.faecalis no statistically significant difference neither between nanoneem and nanocurcumin (p>0.05) nor between nanocurcumin and PDT (p>0.05). While there was a statistically significant difference between nanoneem and PDT (p<0.001). While for C. albicans no statistically significant difference between nanocurcumin and PDT (p>0.05). While the differences were statistically highly significant between nanoneem and PDT (p=0.002) and between nanoneem and nanocurcumin (p<0.001). Conclusion: nanoneem and nanocurcumin irrigants activated by laser have an effect on root canal microorganisms and could be used as adjunctive endodontic irrigant.