This work was carried out with the objective of testing the comparative efficiency of different tests for the evaluation of the physiological quality of cotton seeds (Gossypium hirsutum L.), looking for information that may provide options to improve seed quality control, as well as to verify the relations with field emergence. Six seed lots of cultivar Pima S5 were valued, in the period from March to August 1996, by the germination and vigor tests (first count germination, electrical conductivity, accelerated aging, cold without soil, field emergence and seedling length under hydric levels at 0,0; -0,3; -0,6 and -0,9MPa matric potentials). The trials were carried out in a completely randomized designing with four replications per lot. The results indicated that the accelerated aging, electrical conductivity test, cold without soil and seedling length under stress at -0,3MPa are effective to detect differences of physiological quality among lots of cotton seeds, and at the same time they show the good levels of correlation with field emergence.