In this study, it was aimed to adapt the Technology Proficiency Self-Assessment Scale for 21st Century Learning (TPSA C-21), developed by Christensen and Knezek, into Turkey's conditions. The study sample consisted of 606 teachers working in 58 public schools affiliated to the Ministry of National Education in Bartin province. The original scale had a six-factor structure consisting of 34 items. In the adaptation stage, the Turkish version of the scale was initially created and then retranslated back into the source language. Next, the scale items were evaluated by linguists. Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) were used to determine the construct validity of the scale. As a result of the EFA, some of the items having inappropriate values were excluded from the scale and finally a structure with 24 items and four factors named "E-mail", "WWW", "Integrated Applications", and "Teaching with Technology" was obtained. The results of the CFA showed that the factor structure had adequate fit indexes. For reliability, internal consistency and test-retest correlation coefficients of the whole scale and its sub-dimensions were examined and these values were found to be acceptable. After all, this scale has become a measurement tool that can be used for research which enables educators to make relevant inferences about technology proficiency in 21st century learning.