A study of foraminiferal assemblages was carried out at two Egyptian Nile Delta lagoons. Analysis of surficial sediment samples from Manzalah Lagoon shows enrichment in heavy metals (Pb, Zn, Cu, Cr and Cd). The environment has become so lethal to foraminifera that no species can currently survive. Among ostracods, only one species (Cyprideis torosa) was found living and able to invade the polluted lagoon region. Samples from Edku Lagoon, which receives only agricultural drainage water, show heavy metal concentrations close to natural baseline levels, and yield living foraminifera. The frequent occurrence of deformed specimens in Manzalah Lagoon, comparable to Edku Lagoon, reveals that: (1) benthic foraminifera are more sensitive to industrial wastes containing heavy metals; (2) agricultural wastes do not significantly harm benthic foraminifera; (3) Ammonia beccarii forma parkinsoniana is less resistant to pollution than forma tepida; (4) morphological abnormalities of the foraminiferal tests depend upon the nature of the pollutant; and (5) benthic foraminifera are less tolerant to pollution than ostracods and molluscs.