The present study was conducted during 2021-2022 in Dharwad and Gadag districts of North Karnataka with a specific objective to identify the constraints faced by farmers in adoption of biofertilizer technologies. Sixty farmers each of both districts were identified through simple random sampling method, thus constitutes a total sample of 120 respondents. In the investigation, ex-post facto research design is being employed. The interview schedule was developed based on the objective of the study and review of literature. The information was collected by personal interview method. Constraints and suggestions were analysed using Garrett’s ranking technique and it is observed that lack of required knowledge on biofertilizer technologies ranked first among constraints with garret score 73.00 followed by non-availability of biofertilizers locally at times when needed (71.60), slow results of biofertilizer technologies on different growth stages of crop or on standing crop (65.29), lack of technical guidance about biofertilizer technologies (58.10) and lack of financial support from government (56.00). The important suggestions stated by the farmers for improving adoption of biofertilizer technologies were organization of training/demonstrations on biofertilizer technologies on usage of biofertilizers, need of government support in the form of subsidies on biofertilizers and assured availability of bio-fertilizers in villages.