The aim of this study was evaluate the behavioral responses of rainbow trout (Oncorhynchus mykiss) exposed to changes in temperature and ammonia. For this purpose were placed separately 8 rainbow trout (average weight of 6±2g, length 5±2 cm) in the treatment and control groups with four replicates in five-liter tanks (cross-sections 7 cm, height 4 cm) Each the tanks have a water inlet and outlet. The testing process was divided into three periods the first period was the increase in temperature and ammonia in treatment (first period). Second period includes a fixed value of temperature and ammonia at the highest level of interest in the treatments (middle period). The third period (period end) involves reducing the temperature and ammonia to the initial value at the start of the experiment. Swimming pattern includes six characteristic average swimming speeds, total movement, move summarily, percent move, the average angular change in movement, average distance from center. Results showed that there was a significant difference between pattern of fish swimming in temperature and ammonia treatment compared with the control group (p<0/05). Also, there was a significant difference between treatment swimming patterns, in test first periods compared to the test end periods (p<0/05). The results of this study showed that the pattern of fish swimming in the face of environmental stresses will not only changed, but also has certain patterns. However, this study showed that more reviews behavioral patterns of fish, the effectiveness for monitoring environmental stresses.