Probably the simplest and most comprehensive definition to be made regarding the question of "what is mathematics?" will be that "mathematics is a science of patterns and relationships". It is possible to examine patterns in different levels of difficulty and importance from preschool period to advanced levels. In fact, the robust foundations of advanced algebraic and functional thinking could be established at early ages with the help of patterns. In such an important field of study, investigation of preserves teachers' competencies is thought to contribute to teacher training studies to be conducted in future. The present study was carried out using statistical methods with third-grade preserves teachers from four different programs of the Elementary School Teaching Department at Ziya Gökalp Education Faculty of Dicle University. The research data were collected via pattern activities developed by Olkun and Tanisli (2009). In order to analyze the data collected, t-test, one-way analysis of variance, frequency distributions and Pearson correlation-determination analysis were used. The results of the analysis of the research data revealed that in general, in the field of simple-to-complex patterns, the preserves teachers participating in the study had a high level of competency in the phases of recognition, visualization and verbalization and that they had a medium level of competency in the phases of symbolization and analysis. In the study, no significant differences were found between the preservice teachers' competencies in the acquisition of thinking skills regarding the simple-to-complex patterns with respect to their gender and their programs in the department. When the pattern activities were examined considering the class levels, the preserves teachers reported difficulties due to lack of knowledge at most about the sub-dimensions of "Let's continue the pattern to a far step" for the elementary school 1st and 2nd grades; "Let's determine the relationship" for the elementary school 3rd and 5th grades; and "Let's generalize" and "Let's find a relation" for the elementary school 6th and 8th grades. Regarding the sub-dimensions, no significant difference was revealed in terms of the program and gender. Only for two of the programs, for the purpose of overcoming the lack of knowledge, background information was given about "arithmetic and geometric sequences" prior to the application (Elementary School Teaching and Pre-School Teaching). The pretest posttest study was carried out to investigate the impact of the practical experimental work. The increase in the experimental group was statistically significant (t = 2.05, p <0.05). The addition of application directed research lab to the front and end debate in the laboratory has been shown achievement tests to be effective in the development of science process skills. The findings obtained in the study demonstrated that the preserves teachers involved in the research sample met certain subjects regarding certain sub-dimensions in the field of simple-to-complex patterns as the elementary school level increased and that they did not take any courses covering these subjects. In order to fill the students' knowledge gap, it is believed that it would be useful if comprehensive courses related to "patterns and relationships" are included in the curricula of teacher training institutions.