Spastic gait presents clinically as the net mechanical consequence of neurological impairments of spasticity, weakness, and abnormal synergies and their interactions with the ground reaction force in patients with upper motor neuron syndromes and with some neuromuscular diseases. It is critical to differentiate whether the primary problem is weakness or spasticity, thus better understanding different phenotypes of spastic gait disorders. Pelvic girdle abnormality plays a pivotal role in determining the clinical presentation of gait disorders, since it determines the body vector and compensatory kinetic chain reactions in the knee and ankle joints. Knee joint abnormality can be a mechanical compensation for hip and/or ankle and foot abnormality. Diagnostic nerve blocks and instrumented gait analysis may be needed for diagnosing the underlying problems and developing an individualized plan of care. A wide spectrum of treatment options has been used to manage spastic gait disorders. Some are in early and investigational stages, such as neuromodulation modalities, while others are well-developed, such as therapeutic exercise, ankle-foot orthoses, botulinum toxin treatment, and surgical interventions. Physicians and other healthcare providers who manage spastic gait disorders should be familiar with these treatment options and should employ appropriate interventions concurrently rather than serially. The most effective treatments can be selected based on careful evaluation, inputs from patients, family, and therapists, along with appropriate goal setting. Treatment plans need to be re-evaluated for effectiveness, relevance, and in concordance with disease progress. This is particularly important for patients with progressive neuromuscular diseases such as amyotrophic lateral sclerosis.