Very few experimental studies were found that investigated the impact of learning styles and of teaching critical thinking along with nursing content on students' ability to learn nursing content and to use critical thinking skills. The primary focus of this study was to determine if teaching some the rules and principles of critical thinking and nursing diagnosis will increase Associate Degree Nursing (ADN) students' ability to write accurate nursing diagnoses. A secondary focus was to ascertain the learning style(s) which is/are conducive to learning critical thinking and nursing diagnostic skills. The students involved in this study were enrolled in the Associate Degree Nursing Program at Illinois Central College, East Peoria, Illinois. A quasi-experimental pretest-posttest design was used because it was necessary to use two intact classes as the treatment groups. The experimental group was taught some of the rules and principles of critical thinking, nursing process, and nursing diagnosis. The traditional group was taught some of the rules and principles of nursing process and nursing diagnosis. The data was collected with the following instruments: Watson-Glaser Critical Thinking Appraisal, Kolb's Learning Styles Inventory, and a researcher-developed nursing diagnosis test and an attitude scale. The data were analyzed by using t-tests of true mean scores, analysis of variance, analysis of covariance, and Pearson's r correlation. All hypotheses were tested for significance at the.05 level. From the results of this study, the following conclusions may be drawn regarding teaching selected critical thinking skills along with nursing diagnosis and the nursing process: (1) Nursing diagnosis and critical thinking means of the two groups did not improve. (2) The relationship between nursing diagnosis and critical thinking in the experimental group was strengthened. (3) There was no significant difference between learning styles and critical thinking, but students with assimilator learning styles had higher nursing diagnosis scores. (4) The two instructional methods did not significantly affect the students' attitudes toward using critical thinking skills and the nursing diagnostic process.