In the recent past, the demand for composite materials has increased in the areas of the aircraft parts where service temperature requirement is more than 250 °C. Carbon–polyimide is one amongst such composite material, which is considered as suitable choice to replace metals in aerospace applications with service temperature up to 280 °C while offering potential advantages such as reduced weight and better stiffness. The processing of polyimide composites is difficult as processing happens at 371 °C under vacuum and high pressure. Additionally, the consumable materials used for curing such as vacuum bag, release film, sealing tape and breather would be operating at the limits of their capabilities. Furthermore, the processing parameters have to be optimized to achieve quality required for aerospace applications. Carbon–polyimide prepreg has to be processed through two stages in autoclave curing. The first stage is called devolatilization which is carried out at 177°C, and second stage is called imidization or final curing (polymerization) which is carried out at 371 °C under full vacuum and 12 bar G pressure. In first stage, devolatilization process is carried out to remove the volatiles which otherwise can lead to formation of voids in the cured parts. Therefore, optimization of devolatilization cycle is critical for effective removal of volatiles and achieving better laminate consolidation in subsequent processing stage, i.e., imidization cycle. In this work, laminates are subjected to devolatilization (first stage) at various dwell durations after which all laminates are subjected to identical imidization (second stage) process. Laminates processed with dwell time of 30 min and above results in 16–17% volatiles (by weight) removal which is in agreement with data provided by prepreg supplier. These laminates are inspected using ultrasound technique (C Scan), and the results showed that the laminates had consolidated well for dwelling duration above 30 min and met the required qualification criteria.