Introduction: Parkinson's disease causes reduced motor and cognitive abilities that have a significant impact on the lives of patients and their families. Non-pharmacological procedures, such as exercise, which can reduce movement disturbances, improve motor abilities, cognitive impairment, and quality of life, are therefore very important in patients with Parkinson's disease. Purpose: The purpose of this thesis was to analyze the impact of resistance training on muscle strength of the lower limbs in patients with Parkinson's disease. Methodology: Literature was searched for in English in the PEDRO, PubMED and CINAHL databases. Studies from a systematic review were also reviewed. The following keywords were used alone or in combination: Parkinson's disease, exercise, resistance training, muscle strength, lower limb. Results: According to inclusion and exclusion criterias, ten relevant studies have been found. In examined studies, the duration of the training program was variable, from 7 weeks to 24 weeks. Likewise, in the examined studies, the length of one exercise unit was different from a minimum of 15 minutes to a maximum of 90 minutes. The total number of participants in all ten studies was 556 participants. The strength of lower limb muscles was statistically significantly improved in eight examined studies. Resistance training improved body functions, movement activities, cognitive impairment and quality of life, and reduced the likelihood of falls. Conclusion: The resistance training improves muscle strength of lower limbs in patients with Parkinson’s disease. It has a positive effect on the functions of the nervous system, the muscles and the skeleton, and the movement related functions. It also has a positive effect on movement activities such as balance, walking and mobility. Under proper supervision, resistance training is a pleasant, effective and relatively safe way to improve muscular strength in these patients.