This is a descriptive and exploratory study aiming to analyze the circardian rhythm of oral temperature and classify chronotypes in two groups (56 students and 34 nursing workers). The Horne&Ostberg questionnaire (1976) and digital thermometers were used. The average age of nursing workers was 34.4 years old; and of students was 26.2 years old. Working time showed significant difference (p < 0.0001). Morning students showed cosinor parameters: mesor = 36,4609, amplitude = 0,2335 and acrophase = 14,4658, with p-value = 0.0009; evening students showed mesor = 36,4215, amplitude= 0,2263 and acrophase= 14.3009, with p-value < 0.0001. Morning shift nursing workers presented: mesor = 36,2196, amplitude = 0,4007 and acrophase =15,0746, with p-value < 0.0001. Indifferent chronotype was prevalent for the population of nursing professionals and the evening type for students. The findings showed circadian rhythm.