Meniscal injuries affects 60 to 70 cases per 100,000 people, In the USA, surgical procedures for the meniscus are performed on approximately 850,000 patients each year. The aims of the present study were to; assess knowledge and practice of patients undergoing knee arthroscopy for meniscal trimming, evaluate the effect of applying a rehabilitation guidelines on knowledge and practice of patients undergoing knee arthroscopy for meniscal trimming, and to examine the effect of the rehabilitation guidelines on the outcomes of patients undergoing arthroscopic knee surgery for meniscal trimming. Subjects and methods: A convenient sample of sixty adult patients (male and female) undergoing arthroscopic knee surgery for meniscal trimming were included in this study. The study was conducted at the orthopedic department and arthroscopic out-patient clinic at Assiut University Hospital. Two tools were utilized to fulfill the aims of this study; tool one patient's health needs assessment sheet and it was divided into three parts concerning; patient's sociodemographic characteristics, assessment of patient's physical status using the (modified Cincinnati knee rating scale), and part three was concerned with assessment of patient's knowledge and practices and mid thigh circumference along the four follow up appointments (pre, two weeks, one month and two months post arthroscopic surgery). Tool two represents the rehabilitation guidelines. Results showed that a high statistical significant difference was observed between the study and control groups collectively in all the study periods on the modified Cincinnati knee rating scale, knowledge and practice scores while there was no statistical significant difference in mid thigh circumference. Conclusion: providing written guidelines for patients was much more effective on the outcome of patients who have undergone arthroscopic knee surgery for meniscal trimming than those patients in the control group who received resident's oral instructions. Recommendations: a nurse rehabilitator is of great value in both the orthopedic department and the out-patient arthroscopy clinic and a rehabilitation instructions booklet is of great importance for the patients.