The purpose of this study is to investigate the relationship between some of selected affective characteristics of high school students related to physics lesson and their physics achievement in electricity concept. These affective characteristics of the students includes their interest in physics, importance of physics, enjoyment of extra-curricular activities related to physics, physics course anxiety, physics test anxiety, achievement motivation in physics, student motivation in physics, self-efficacy in physics and self-concept in physics. Two causal models explaining the direction of the relationship between these affective characteristics and physics achievement was hypothesized and tested. A questionnaire consisted of 10 sub-dimensions was used in order to determine the affective characteristics of high school students. The achievement scores were obtained by using Ninth Grade Electricity Test developed by the researcher. The Ninth Grade Electricity Test includes 29 items about the electricity concept. The Ninth Grade Electricity Test and the Affective Characteristics Scale were administered to 1457 students in 22 foreign language high schools in Ankara when they start to tenth grade in 2004-2005 academic year. The researcher was the data collector and was present in the class during administration of scale and test. The preliminary analyses were conducted by using Excel and SPSS 10.0 and the confirmatory analysis and testing of the hypothesized structural models were conducted by LISREL 8.30 for Windows. The findings indicated that achievement in physics has a significant effect on high school students&rsquo / affective characteristics. Since, affective characteristics of students are effective on achievement in later years, they should be firmly formed at high school years. Besides, affective characteristics should be improved whether they have an effect on achievement or not, because they have an effect on persistence in from of selection of courses which also may give the chance of being successful in a subject to a student.