Little is known about respiratory tract infection (RTI) severity in children following consultation. To investigate post-consultation symptom trajectories in children with acute cough and RTI and whether baseline characteristics predict trajectory group. Prospective cohort study of 2296 children (3 months-16 years) whose parents were invited to report cough severity and duration using a 7-point Likert scale. Longitudinal latent class analysis (LLCA) was used to identify post-consultation symptom trajectories in the first 15 days, and multinomial models to predict class membership. Complete data were available for 1408 children (61%). The best LLCA model identified five post-consultation symptom trajectory groups: 'very rapid recovery' (28.5%), 'rapid recovery' (37.7%), 'intermediate recovery' (18.2%), 'persistent symptoms' (9.5%) and 'initial deterioration with persistent symptoms' (6.0%). Compared with very rapid recovery, parent-reported severe cough in the 24 hours prior to consultation increased the likelihood of rapid recovery (OR 1.79 95% CI 1.23, 2.60), intermediate recovery (OR 2.13 1.38, 3.30 and initial deterioration with persistent symptoms (OR 2.29 1.26, 4.16). Initial deterioration was also associated with 'severe barking cough' (OR 3.64 1.50, 8.82), 'severely reduced energy in the 24 hours prior to consultation' (OR 3.80 1.62, 8.87 and higher parent-assessed illness severity at consultation (OR 2.21 1.17, 4.18). We identified five distinct symptom trajectory groups showing the majority of children improved post-consultation, with only one group experiencing illness deterioration. The few characteristics associated with group membership did not fall into a pattern that seemed clinically useful.