Spasticity is a common disorder in neurological patients. It causes an involuntary or sustained activity of the muscles and it is usually accompanied by weakness and loss of function. Resistance training could thus be an interesting therapeutic tool, so the objective of this review was to analyze the current literature on this type of exercise in spasticity, strength and function in this population. For this, a search was carried out in MEDLINE, CINAHL and SCOPUS and a total of 10 randomized controlled trials were obtained to carry out the analysis. In line with other research, it appears that resistance exercise does not worsen spasticity and could also improve the strength and functionality of these patients, so its practice under appropriate professional supervision is strongly recommended.