The transgenerational reproductive and developmental toxicity of tebuconazole (TEB) in Caenorhabditis elegans was investigated over five generations (P0 - F4). Only parental C.elegans (P0) were exposed to TEB (0, 0.01, 0.1, 1, and 10 μg/L) for 24 h and the subsequent offspring (F1-F4) were grown under TEB-free conditions. TEB exposure caused dose-dependent reproductive defects and developmental impairments in C.elegans. In the P0 generation reproductive defects were observed such as: reduced brood size and embryo hatchability, prolonged generation time, retarded gonadal development, and slower germline proliferation, even at 0.01 μg/L, together with developmental toxicity with significant reduced body length and narrowed body width at 10 μg/L. Additionally, the brood size significantly reduced in F2, which began to recover from F3, but was still lower than the control in F4. The proportion of abnormalities increased significantly in F2 and reduced from F3, but was still higher than the control, suggesting that TEB could have cumulative potential and be passed to offspring through parental exposure. Furthermore, exposure to TEB (10 μg/L) in P0 significantly reduced the body length in F1, which began to recover from F2, and was the same level as the control in F4. There was a concentration-dependent increase in body width in F1-F4, with a significant increase only observed in F1 at 10 μg/L. Thus, parental exposure to TEB induced transgenerational defects in both reproduction and development, emphasizing the significance of considering bio-toxicity over multiple generations to conduct accurate assessment of environmental risks of toxicants.