The study aimed to reveal the relationship between Vocational Interests and the level of Aspiration and Perfectionism among grade 10 & 11 students in Muscat Governorate Schools according to the gender and grade variables. The study was conducted on a sample of 10th and 11th grade students in Muscat Governorate in the academic year (2016/2017). The researcher used the correlation descriptive method for this study. The sample of the study was (520) students, (289) males and (231) females. For the purpose of the study, the researcher adopted three scales: the John Holland Scale to measure the vocational interests, constructed by Ministry of Education in Oman (2015), and the (Abdel Atheem & Muawath, 2005) scale to measure the level of aspiration, and the (Frost, et al., 1999) scale to measure the level of Perfectionism. The most prominent results of the current study were as follows: 1. The most common Vocational Interests in the study sample were Conventional followed by Social, then Enterprising, Investigative, followed by Artistic, then Realistic 2. The level of Aspiration in the study sample, in the scale as a whole, and in all dimensions was high. 3. The level of perfectionism was high in the scale as a whole, and the score varied in all dimensions of the perfectionism scale as follows: Concern Over Mistakes was average level of perfectionism, Parental expectations and personal standards were high level, and the organization was very high. 4. Positive correlation relationship between all vocational environments and the level of aspiration and perfectionism, and a positive correlation relationship between the level of aspiration and perfectionism. 5. There are statistically significant differences between males and females in the Realistic environment in favor of males, and in the Artistic environment and Enterprising for the benefit of females, and the absence of differences in the Investigative, Social and Conventional environments. 6. There are no statistically significant differences in the total score and in all dimensions of the level of aspiration scale depending on the gender variable, except in the Optimism dimension for the benefit of females. 7. There are statistically significant differences in the level of perfectionism in dimensions of Concern over Mistakes and in Parental Expectations in favor of males, and there are no differences in the dimensions of Organization and Personal Standards. 8. There are no statistically significant differences in the vocational interests according to the grade (tenth and eleventh). 9. There are statistically significant differences between the level of aspiration and grade in the Optimism dimension for the benefit of the students of grade ten. 10. There are no statistically significant differences between the level of Perfectionism and the grade..