Background Chimeric anterolateral thigh free flaps (ALT) have been commonly used for head and neck defects, which require two epithelial lined surfaces. However, because of unpredictable vascular anatomy, it is a challenge to consistently elevate large chimeric flaps with multiple perforators based on the Lateral Circumflex Femoral Artery (LCFA). Here, we present our method to reliably harvest a chimeric flap from the ALT territory and investigate its long-term outcomes when used in the reconstruction of extensive head and neck defects. Methods A prospective review of practice consisting of 27 patients, between January 2011 and April 2019, with extensive through-and-through head and neck defects, which require dual paddle flaps underwent reconstruction with chimeric ALT harvested with a portion of distal vastus lateralis. The age of the patients ranged from 32 to 68 years (mean 53.2 years). Results Flap length ranged from 17 to 30 cm (mean, 25.6 cm). The mean flap area was 261.6 cm2 (range, from 225 to 340 cm2). The mean ischemia time was 162.9 min (range, from 59 to 269 min). At a mean follow-up time of 33.4 months (range, from 4 to 91 months), four patients died of cancer recurrence. For the other 23 patients, 4 required revision to achieve better cosmetic lip competence. All flaps survived with two recorded returns to theater for pedicle exploration associated with partial flap loss only. Conclusion Harvesting the chimeric ALT with a portion of vastus lateralis distally negates the need for tenuous intramuscular perforator dissection. It is a reliable option for head and neck surgery, which require composite reconstruction. Using this technique produces a good functional cosmetic outcome. It also allows large defects to be reconstructed in a single sitting with free tissue transfer. Chimeric anterolateral thigh free flaps (ALT) have been commonly used for head and neck defects, which require two epithelial lined surfaces. However, because of unpredictable vascular anatomy, it is a challenge to consistently elevate large chimeric flaps with multiple perforators based on the Lateral Circumflex Femoral Artery (LCFA). Here, we present our method to reliably harvest a chimeric flap from the ALT territory and investigate its long-term outcomes when used in the reconstruction of extensive head and neck defects. A prospective review of practice consisting of 27 patients, between January 2011 and April 2019, with extensive through-and-through head and neck defects, which require dual paddle flaps underwent reconstruction with chimeric ALT harvested with a portion of distal vastus lateralis. The age of the patients ranged from 32 to 68 years (mean 53.2 years). Flap length ranged from 17 to 30 cm (mean, 25.6 cm). The mean flap area was 261.6 cm2 (range, from 225 to 340 cm2). The mean ischemia time was 162.9 min (range, from 59 to 269 min). At a mean follow-up time of 33.4 months (range, from 4 to 91 months), four patients died of cancer recurrence. For the other 23 patients, 4 required revision to achieve better cosmetic lip competence. All flaps survived with two recorded returns to theater for pedicle exploration associated with partial flap loss only. Harvesting the chimeric ALT with a portion of vastus lateralis distally negates the need for tenuous intramuscular perforator dissection. It is a reliable option for head and neck surgery, which require composite reconstruction. Using this technique produces a good functional cosmetic outcome. It also allows large defects to be reconstructed in a single sitting with free tissue transfer.