Law offices of PILLSBURY MADISON & SUTRO LLP 2700 Sand Hill Road Los Angeles MENLO PARK, CALIFRONIA 94025-7020 Menlo Park New York Telephone (415) 233-4500 Orange County Sacramento Telecopier (415) 233-4545 San Diego Washington, D.C. San Jose Tokyo Hong Kong - -------- Writer's Direct Dial Number September 11, 1996 NETCOM On-Line Communication Services, Inc. 2 North Second Street San Jose, CA 95113 Re: Registration Statement on Form S-8 Ladies and Gentlemen: With reference to the Registration Statement on Form S-8 to be filed by NETCOM On-Line Communication Services, Inc., a Delaware corporation (the "Company"), with the Securities and Exchange Commission under the Securities Act of 1933, relating to 832,142 shares of the Company's common stock, $.01 par value, and the Series C Preferred Stock Purchase Rights associated therewith (the "Common Stock"), issuable pursuant to the Company's Amended and Restated 1993 Stock Option Plan (the "Plan"), it is our opinion that the Common Stock, when issued and sold in accordance with the Plan, will be legally issued, fully paid and nonassessable. We hereby consent to the filing of this opinion with the Securities and Exchange Commission as Exhibit 5.1 to the Registration Statement. Very truly yours, /S/ PILLSBURY MADISON & SUTRO LLP 08212