Every hospital should provide training activities that are challenging, and lead to improving the quality of health services. The aim of the study is to assess the nurses’ perception about the effectiveness of in-service training activities at governmental hospitals in Gaza Strip. The study utilized descriptive, cross sectional, analytical design. The sample of the study consisted of 337 nurses who attended at least one in-service training activity, selected by non-probability, proportional sampling method from seven governmental hospitals in Gaza Strip: 5 general hospitals (Indonesy hospital, Al Shifa hospital, Al Aqsa hospital, Nasser hospital, European Gaza Hospital), one Pediatric hospitals (Al Nassr hospital), and one Maternity hospitals (Al Emaraty hospital). For data collection, the researcher prepared a self-administered questionnaire to measure the nurses’ perception about the effectiveness of in-service training activities. The scoring of the items of the questionnaire is according to the 5-points Likert scale. A pilot study was conducted on 28 participants to examine the validity and reliability of the questionnaire, and alpha coefficient was 0.918.