<![CDATA[Introduction: The quality of health center services is influenced by various factors, including the proficiency of analysts in performing fundamental tests such as Gram staining. This skill is of critical importance for ensuring the accurate interpretation of results, ensuring that therapy and treatment is in accordance with standard practices. However, the competence of health analysts in the health center's working area varies considerably, which has the potential to affect the interpretation of test results. The objective of this activity was to enhance the knowledge and skills of health analysts at Puskesmas in Jayapura City in performing Gram staining.Methods: This study used a pre-experimental one-group pretest–posttest design (without a control group). The activity was carried out in Jayapura in June 2025, during a one-day training session. The research population consisted of all laboratory analysts who participated, with 11 participants who met the inclusion criteria included as samples using total sampling techniques. Knowledge assessment was conducted using a multiple-choice questionnaire. The data were analyzed descriptively to describe the characteristics of the respondents and the distribution of scores, as well as inferentially using a paired t-test to compare the mean pre-test and post-test scores, with a significance level of 0.05.Results: The implementation of gram staining training resulted in a significant enhancement in the average knowledge score, which increased from 4.45 to 6.73 (an increase of 2.27 points). A statistically significant difference was identified between the pre-test and post-test scores (t(10) = 2.46; p = 0.034), exhibiting a medium-to-large effect size (Cohen's dz = 0.74).Conclusion: The impact of gram staining training on learning outcomes was significant, with a moderate to large effect size (Cohen's dz = 0.74). However, it is important to note that the assessment of skills not included in this study is also necessary.]]>
