Aim: To evaluate the effect of final HbA1c levels on the incidences of hypoglycaemia in participants with type 1 diabetes treated with inhaled Technosphere® Insulin or subcutaneous insulin aspart, reported in alignment with the International Hypoglycaemia Study Group recommendations. Methods: In the randomized, phase 3, multicentre AFFINITY-1 study, adults (N = 375) who had type 1 diabetes for ≥ 12 months and an HbA1c level of 58–86 mmol/mol (7.5–10.0%) were randomized to receive basal insulin plus either inhaled Technosphere Insulin or subcutaneous insulin aspart. This was a post-hoc regression analysis on a subset (N = 279) of the randomized AFFINITY-1 cohort for whom baseline and end-of-treatment HbA1c values were reported. Primary outcome measures were incidence and event rates for levels 1, 2 and 3 hypoglycaemia, respectively defined as blood glucose levels of ≤ 3.9 mmol/l, < 3.0 mmol/l or requiring external assistance for recovery. Results: Participants treated with Technosphere Insulin experienced statistically significantly fewer level 1 and 2 hypoglycaemic events and a lower incidence of level 3 hypoglycaemia than participants treated with insulin aspart. The lower rate of hypoglycaemia with Technosphere Insulin was observed across the range of end-of-treatment HbA1c levels. Technosphere Insulin was associated with higher rates of hypoglycaemia 30–60 min after meals, but significantly lower rates 2–6 h after meals. Conclusions: Participants using Technosphere Insulin experienced clinically non-inferior glycaemic control and lower hypoglycaemia rates across a range of HbA1c levels compared with participants receiving insulin aspart. ClinicalTrials.gov: NCT01445951.