Total revenue for the third quarter of 2022 was $84.7 million, representing growth of 15% over the third quarter of 2021. Excluding $7.7 million revenue from Pinnacle 21, which was acquired in late 2021, revenue increased $3.0 million, or 4%. The increase in revenue was primarily due to growth in our technology-driven services and software product offerings from strong renewal rates, client expansion, and new customers. The increase was partially offset by the negative impact on our revenue from fluctuation in the foreign currency exchange rates.
On a constant currency basis, total revenue for the third quarter of 2022 was $87.5 million, representing growth of 18% over the third quarter of 2021. Excluding $7.7 million of revenue from Pinnacle 21, the revenue on a constant currency basis increased $5.9 million, or 8%. Please see note (1) in the section A Note on Non-GAAP Financial Measures below for more information on constant currency revenue.
Total cost of revenue for the third quarter of 2022 was $32.8 million, an increase of $4.0 million from $28.8 million in the third quarter of 2021, primarily due to a $1.6 million increase in intangible assets amortization, a $1.0 million increase in stock-based compensation cost, a $0.4 million increase in employee-related costs resulting from billable headcount growth, a $0.4 million increase in equipment and travel expenses, and a $0.5 million increase related to cost of licenses.
Total operating expenses for the third quarter of 2022 were $41.0 million, decreased by $4.9 million from $45.9 million in the third quarter of 2021, primarily due to a $7.5 million decrease in business acquisition costs, a $2.4 million decrease in stock-based compensation costs, a $0.9 million increase in capitalized cost in research and development, partially offset by a $3.9 million increase in employee-related costs, a $1.0 million increase in intangible asset amortization, a $0.4 million increase in public offering cost, and a $0.4 million increase in travel expenses.
Net income for the third quarter of 2022 was $3.9 million, compared to a net loss of $1.8 million in the third quarter of 2021. The $5.7 million increase in net income was primarily due to a $10.8 million increase in total revenue, a $4.9 million decrease in operating expenses, a $2.0 million currency gain, partially offset by a $4.0 million increase in cost of revenue, and $6.2 million increase in tax expense. and $1.9 million increase in interest expense.
Diluted earnings per share for the third quarter 2022 was $0.02, as compared to $(0.01) in the third quarter of 2021.
Adjusted EBITDA for the third quarter of 2022 was $32.7 million compared to $26.1 million for the third quarter of 2021, representing 25% growth. See note (2) in the section A Note on Non-GAAP Financial Measures below for more information on adjusted EBITDA.
Adjusted net income for the third quarter of 2022 was $16.6 million compared to $17.2 million for the third quarter of 2021. Adjusted diluted earnings per share for the third quarter 2022 was $0.10 compared to $0.11 for the third quarter of 2021. See note (3) in the section A Note on Non-GAAP Financial Measures below for more information on adjusted net income and adjusted diluted earnings per share.