Bu-Olayan and Thomas: Validating species diversity of benthic organisms to trace metal pollution - Abstract. Benthic organisms diversity were observed in the sequence of Annelida > Mollusca > Crustacea > "Diversa" group. Levels of trace metals in benthic organisms were in the range 0.12-96.86 µg/g during winter and 0.98-54.13 µg/g in summer. Species diversity index (H'), evenness index (J) and index of dominance (λ) were in the range 0.951-1.368 bits/unit, 0.475-0.684, and 0.19-0.33 respectively, for benthic organisms sampled in Kuwait Bay sites. Evenness index (-) was found to increase with increasing H'. Seasonally, an inverse correlation was observed between species richness (R1 and R2).Comparative studies revealed low diversity indices correspondingly to the increase in trace metal level in benthic species collected from four sites except Doha wherein high abundance of certain benthic species and high trace metal levels due to manmade perturbations were observed altering the diversity indices. Furthermore, these indices will validate benthic organisms as an indicator to trace metal pollution in Kuwait marine ecosystem.