Plantago maritima grown under saline conditions accumulates large quantities of sodium chloride. Salinity reduces tissue potassium, calcium and magnesium contents. Several enzymes from P. maritima are shown to be salt-sensitive. In contrast to many other higher plant halophytes, P. maritima shows no accumulation of either amino acids or methylated onium compounds. High levels of the polyhydric alcohol sorbitol are however accumulated under saline conditions. The possible role of sorbitol as a compatible cytoplasmic solute is discussed.