Humic substances (HS) are known as stimulators of seed germination and plant growth. Here we have examined the influence of HS obtained from the extract of a mixture of brown coal and industrial waste of red seaweed, Ahnfeltia tobuchiensis (HS-Ahnfeltia), on the germination of maize seeds. Seeds of Zea mays L. were immersed in HS-Ahnfeltia (treatment) or water (control) and germinated on moist filter paper in sealed Petri dishes. After 5 days of incubation at 28°C, the results showed that treatment with HS-Ahnfeltia promoted seedling growth. While no significant differences occurred in seed emergence, an important increase in root (36%) and shoot (54%) area as well as root (100%) and shoot (54%) dry weight was observed in treated seedlings, resulting in a 100% increase of the seedling vigour. These results suggest that HS-Ahnfeltia extract can be used as an effective agent to increase seedling vigour in crops.