Niger seed is commonly known as "noug" and is Ethiopia's second most produced oilseed crop. The byproduct of niger seed obtained after the removal of most of its oil is known as niger seed cake which is used as nutritious livestock feed. Oilseed cakes, particularly niger seed cake, are susceptible to mold infection and mycotoxin production. Mycotoxins are toxic secondary metabolites produced by different toxigenic mold species. This study aimed to investigate the incidences and levels of total aflatoxins (AFT), ochratoxin A (OTA), deoxynivalenol (DON), and fumonisin (FUM) in niger seed cake samples collected from oil millers and LSFs(livestock farmers) in Bahir Dar and nearby towns, and to identify niger seed cake storage techniques suitable for prevention of mold growth and mycotoxin accumulation. A total of 43 niger seed cake samples were collected from Bahir Dar, Wereta, and Meshenti towns. For the controlled laboratory experiment, niger seed cake was produced in the lab by mechanical pressing of niger seed obtained from the Bahir Dar market. A completely randomized design was implemented to investigate the effect of three storage bag types on the accumulation of mycotoxins over three months. The storage bags were hermetic bags (PICS and GrainPro bags) and woven polypropylene bags (PPB), each replicated three times. Mycotoxins were analyzed using the lateral flow immunoassay principle on an indirect competitive immunoassay format. Descriptive statistics, ANOVA, t-test, and correlation analysis were performed for data analysis at a 5% significance level. Results were reported in two separate parts: the survey and the controlled experiment. In the survey samples, the incidence of AFT, OTA, FUM, and DON were 100%, 86.1%, 0%, and 0%, respectively. Levels in positive samples ranged from 5 to 52μg/kg for AFT and 2.5 to 11μg/kg for OTA. Besides, the sampling location and operator types had no significant effect on the occurrence of AFT and OTA. Regarding the controlled storage experiment, niger seed cake stored in the PPB for three months showed higher AFT, OTA, and increased mold count than baseline levels. Niger seed cakes in the PICS and GrainPro bags did not show significant changes in the tested parameters over the three months. The output of this investigation evidenced the occurrence of mycotoxins in niger seed cakes of the study areas. Moreover, hermetic bags were superior to the PPB for the niger seed cake storage. Therefore, creating awareness and facilitating access to hermetic bags is essential to prevent mycotoxin development and associated human and animal health risks. Keywords: Mycotoxin, niger-seed cake, occurrence, storage bag, livestock, oil-miller, study-location, handling practice