ABSTRACT. – Internal waves in the Bay of La Paz, southern Gulf of California, Mexico, are evidenced by variations in vertical profiles of chlorophyll-a and temperature, which showed vertical displacements between down-up cast profiles, and by satellite images. The maximum peaks in the natural fluorescence of chlorophyll-a and the thermocline depth were used to compare the differences between the two profiles. The results showed that the maximum displacement in chlorophyll-a was 4.4 m, while the maximum displacement in the thermocline depth was 8.7 m; the elapsed mean time between down-up profiles was 11.6 min. It was possible to reproduce the structure of the internal wave along the bay. The wavelength, obtained from satellite images, in the north and south part of the bay, is 3.11 km, while in the central part it is 15.56 km. The mechanisms of generation of the internal waves observed could be in association with the currents interacting with a bathymetric sill at the connection with the gulf. This study suggests that the internal waves can manifest in the area over short distances and can be inferred by different processes, such as vertical chlorophyll-a and temperature profiles and by satellite images.