A pot experiment was carried out at the Experimental Farm, Faculty of Agriculture, Al-Azhar University, Assiut, Egypt during 2021/2022 and 2022/2023 growing seasons to elucidate the impact of filter mud as organic manure, microorganisms as biofertilizers and their interactions on herb dry weight, flowers dry weight, seed yield, fixed oil % as well as the content of alkaloids in the herb, flowers and seeds of borage (Borago officinalis L.) plants. Filter mud was added at four levels (0, 70, 140 and 210 g/plant) compared with the check treatments. Microorganisms as biofertilizers used were eight treatments as follows: 0 (uninoculated plants), Azotobacter chroococcum (Az), Bacillus circulans (B.c), arbuscular mycorrhiza fungi (Glomus mosseae and Glomus fasciculatum) (AM), Az + B.c., Az + AM, B.c + AM and Az + B.c + AM. The obtained results indicated that the addition of filter mud with all levels resulted in a significant increase in all studied aspects, except for the low one (70 g/plant), mostly. Clearly, in the most cases, the tested parameters were gradually significantly augmented with increasing the levels of filter mud. Therefore, the filter mud when used at high level (210 g/plant) proved to be more effective in elevating the examined characteristics. At the same time, the inoculation with the tested useful microorganisms either single or in combination led to a significant increase in the studied traits, except Azotobacter (Az) and or Bacillus (B.c) treatments, mostly. It is obvious from data that the best results of all traits were detected when the inoculation with the triple combined treatment (Az + B.c + AM), followed by the double combined one (B.c + A.M), mostly. The interaction between the two studied factors on the examined parameters was significant effected. In addition, most combined treatments significantly increased the studied traits. Apparently, supplying the plants with the filter mud at high level (210 g/plant) plus the inoculation with the triple combined treatment (Az + B.c + AM), followed by the double combined one (B.c + AM) were the most effective treatments in augmenting these aspects, in many cases.