This study compares the toxicological response of the marine bacteria Vibrio fischeri and a lux‐modified soil and freshwater bacteria, Pseudomonas fluorescens, to saline contamination alone and in the presence of chromium and phenol. Saline solutions are more toxic to P. fluorescens than V. fischeri, and salinity can stimulate luminescence in V. fischeri. Vibrio fischeri is about 10 times more sensitive than P. fluorescens to chromium and phenol. However, the response of P. fluorescens to these toxicants is sensitive to changes in saline contamination, while the response of V. fischeri is not. Therefore, the P. fluorescens bioassay may be a more appropriate bioassay organism than V. fischeri when evaluating the toxicological impact of salinity within saline environmental samples.