Objectives: To evaluate the change in BMI (zscore), FEV1 (% predicted) and number of respiratory exacerbation before and after lockdown 2020 and compare that to the same period in 2019. To establish if there were any differences between the cohorts receiving precision medication compared to the cohort who did not qualify for precision medication. Methods: This was a retrospective case note review of all children with CF attending SCH. Exclusion criteria included children under the age of 2 and pancreatic sufficient patients. Results: Ninety-five children met the inclusion criteria and had their case notes reviewed. Ninety-five had information regarding their exacerbation status, 85 patients had the correct information to calculate their BMI z-score and 49 had FEV1 information. The results are as follows: Conclusion: Our data suggests that the period of lockdown was beneficial for all SCFT CF patients across the measured parameters (BMI, FEV1 and respiratory exacerbation rate) in comparison to the previous year. This benefit was marginally greater for those on precision medicines. The impact of the lifting of lockdown on these parameters in this population will help ascertain the ongoing benefits of precision medicine in this age group.